By on January 2, 2014

OLYMPUS DIGITAL CAMERATTAC reader Dean Trombetta sent us an article on anti-freeze resistant nylon and its applications in the automotive world.

In early 2011, a class action lawsuit was filed against Porsche alleging that the company knowingly installed defective coolant pipes made of nylon into engines of Cayenne model SUV’s. Apparently, the pipes are very likely to fail prematurely resulting in serious engine damage. If the vehicle is out of warranty, customers end up spending big bucks to repair their engines and replace the coolant pipes. The replacement coolant pipes are made of aluminum.

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Most of the readers here probably know that this is not the first time that plastic coolant fittings have failed in a spectacular fashion. In the early 2000′s Ford settled a class action lawsuit brought by owners of various vehicles that had 4.6L V-8′s with intake manifolds made of Nylon. These intake manifolds failed at the coolant passage. The intake manifold was replaced with a new design in which the coolant passage was made of… you guessed it, aluminum.

DuPont was at the forefront of the drive to use Nylon, specifically Glass Fiber reinforced Nylon 6/6 for engine parts starting with radiator end caps which were first adopted by Ford in 1986. Later, in 1996, the first intake manifolds manufactured from the same material started appearing on cars. Nylon intake manifolds have since become ubiquitous and I think that the technology is proven at this point. There are several advantages of using plastic in place of steel or aluminum for intake manifolds. The plastic intake manifolds are lighter weight, the passages can be made smoother which helps deliver fuel more efficiently and probably the number one reason is that they keep the fuel cooler helping the engine run better.

The nylon is typically glass fiber reinforced containing 30-35% by weight what is called “short glass fiber” in the industry meaning that the fibers are approximately 1/16 inches long. The glass fiber adds enormous tensile strength and rigidity to the material. Unreinforced nylon 6/6 has a tensile strength of approximately 12,000 psi while 35% glass fiber reinforcement bumps the tensile strength up to roughly 28,000 psi. This is approaching the tensile strength of some softer grades of steel. Nylon by itself would not bond to glass very well. To facilitate the marriage of these two materials, the glass fiber is coated with proprietary “coupling agents” that allow the nylon to bond to it.

Compared to standard glass fiber reinforced grades of nylon, the anti-freeze resistant grades use better coupling agents as well as heat stabilizers to help the plastic hold up to the elevated temperatures better. The anti-freeze and the organic acids that have been added to anti-freeze in recent years as corrosion inhibitors are thought to attack the bond between the glass fiber and the nylon thus weakening the material.

Whatever is going on chemically, one thing is for sure, the damage done to the nylon over time is severe. A little perusing of the DuPont website revealed a little bit of data on the affects. First to be clear, nylon materials are typically tested in what is called a “dry as molded” condition. The properties of nylon are severely affected by humidity, so in order to maintain some consistency of test results, testing is always performed on specimens that are taken right off of the molding machine and sealed into air tight containers. Here is what we would expect for tensile strength dry as molded and then after being exposed to a 100% relative humidity environment and then finally after prolonged exposure to engine coolant.

Typical Nylon 6/6 35% Glass Fiber Reinforced Tensile Strength

Dry as molded  at 23C                                                     29000 psi

24 hrs at 100% relative humidity at 23C                   11600 psi

24 hrs at 100% relative humidity at 130C                8265 psi

1000 hrs exposure to 50/50 Zerex® at 130C          5800 psi

5000 hrs exposure to 50/50 Zerex® at 130C          1450 psi

As you can see exposure to the anti-freeze has a significant impact on the properties of the material and this is under ideal conditions. Molded test specimens are designed to produce consistent test results and do not typically have the molding variations that will be experienced in production parts that are cranked out by the tens of thousands. These parts can have significantly lower properties than we see here.

I suppose an automaker could make the claim that these parts are considered wear items and must be replaced as part of regular maintenance. But, I would suggest that a customer buys a car with the expectation of not having to replace major engine components for a reasonable length of time. Furthermore, any components whose failure will cause catastrophic damage to other engine components should be built to last a very long time. Unfortunately, the history and the data seem to indicate that the plastics that are currently being used for parts exposed to engine coolant are not really suitable.

 

 

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127 Comments on “Ur-Turn: Not Your Grandmother’s Nylons...”


  • avatar
    Detroit-X

    Automakers can GTFH if they are going to call every one of their poor designs “wear items.”

    It’s things like this that are forced on us in the quest to save mass, for EPA mileage cycles for “better MPG.” The part failure severely negates an owner’s miniscule MPG contribution.

    And I wonder what the net loss in energy expended of vehicles crushed before their time is, compared to energy saved via MPGs?

    • 0 avatar
      jz78817

      “Automakers can GTFH if they are going to call every one of their poor designs “wear items.””

      I don’t see where they are. That was the author’s supposition.

    • 0 avatar
      MK

      “It’s things like this that are forced on us in the quest to save mass, for EPA mileage cycles for “better MPG.” The part failure severely negates an owner’s miniscule MPG contribution.”

      As long as we’re making WAG’s ill say that it’s much more likely these decisions at the manufacturer come down to the cost difference between a cast aluminum piece and a grp piece rather than EPA mandates.

      But I’m willing to get my pitchfork and a carbon-neutral torch if you have any evidence to the contrary.

  • avatar
    felix

    “OK team, we have an important decision to make. We could spend an extra couple of bucks per unit to install parts that will last the lifetime of the vehicle. Or we can save those couple of bucks with cheap parts that WILL fail long after the warranty runs out, thereby earning us a bunch of additional income from sales of replacement parts and engines PLUS keep our dealers happy with lots of billable service hours.”

    “But… but… but sir, wouldn’t that turn our customers against us?”

    “Nah. Once their old cars get too expensive to fix, they’ll just trade them in with us for the latest model.”

    “Um…”

    • 0 avatar
      raph

      I don’t think that line of reasoning is far from the truth. My old man used to gauge the cost of maintaining an old vehicle versus what he could afford new and if the payments beat out the frustration and inconvenience of repairing an old vehicle off to the trade in lot it went economics be damned.

      This also seems to be the same line of reasoning in the luxury boat market and raw water cooling systems. I can’t for the life of me figure why somebody would suck sea water through an engine with all the crap suspended in it especially with aluminum. In the engines that cocktail of microscopic marine life and sand would get squeezed and baked into the coolant passages making the engines run hot over time and even the coated aluminum parts would fail due to corrosion as the salt water and sand either wore it away or found imperfections in the coating.

      I asked a fairly wealthy guy about this and he said; ” That’s somebody else’s problem, I don’t keep them long enough for that to happen”

      • 0 avatar
        DC Bruce

        Other than perhaps outboards (which I know nothing about), I seriously doubt that any inboard boat engine has a cooling system that uses sea water in the engine. Typically, the engine has a closed loop cooling system (just like in other applications) and there is a water-to-water heat exchanger between that system and an open loop system that uses sea water. Even the little 30 hp engines installed in sailboats use that kind of system. Perhaps 35 years ago it was different. In 1980 I had a 30-foot sailboat that had a 12 hp one-cylinder diesel that was cooled directly by sea water, and sailboats made in the 1970s often had inboard gasoline engines that were cooled directly by sea water.

        But, for the reasons you say, that practice has been abandoned at least in inboard engines. Outboards may be another matter.

        • 0 avatar
          celebrity208

          Ralph is correct. From what I see on the used market a significant number of single and twin I/O powered runabouts and cruisers use raw water cooling. I strongly suspect it is a decision made using the same logic as Ralph’s “fairly wealthy” acquaintance.

          • 0 avatar
            bball40dtw

            I wouldn’t want a ocean going yacht with a raw water system. Especially for a high end yacht. Its fine that my Four Winns in Michigan has a raw water system. However, if I ever put it in salt water, I would convert it to a closed system. Some places sell kits for under $1000.

          • 0 avatar
            stuart

            Ditto.

            Virtually all small pleasure boats intended for fresh water have “raw water cooling”, or “lake water in your cast-iron engine block”. And yes, the blocks are horribly corroded after a few hours use.

            To confirm, check out the Mercruiser or Volvo-Penta websites. Not only are the blocks cooled with lake water, the blocks are electrically connected to the aluminum sterndrives. There are zincs attached to the sterndrive legs, and they clearly protect the aluminum, but the iron… Just open the thermostat housing, and it’s all rust-brown. :-P

            Interestingly, I gather they hold up pretty well in salt water. The weak point seems to be the water-cooled exhaust manifolds; I understand that a saltwater-cooled engine block will outlast several sets of exhaust manifolds.

          • 0 avatar
            johnny ro

            It gets worse our on the mass market waterfront. Rubber impeller pumps pumping salt water. Positive displacement, but fail in service.

      • 0 avatar
        danio3834

        It’s definitely true to a point. I remember in the first article about the failures on the Cayenne, an anecdote about an affected owner was presented. While he was pissed that his first Cayenne experienced this major failure, it didn’t stop him from buying 2 subsequent Cayennes.

        Some companies can afford to abuse their customer bases a bit I suppose.

  • avatar
    Morea

    Why are the intake manifolds coming in contact with coolant?

    • 0 avatar
      greaseyknight

      The vast majority of intake manifolds have coolant passages running thru them. Both to feed coolant to the cylinder head, and to keep the intake charge at a consistent temperature, thus preventing icing.

      • 0 avatar
        lzaffuto

        So much so that intake manifold coolant bypass modifications are popular in southern climates. If I remember correctly, manufacturers do it for northern climates that freeze to warm up the manifold faster for better emissions.

      • 0 avatar
        racebeer

        Yep … just ask those of us who suffered through the GM DexCool fiasco on the 3800 V6 engines about the coolant circulation between the head and intake manifold. Except in this case it was the upper/lower intake manifold gaskets, not the manifold itself that was the failure point. Unfortunately I encountered the problem 11 years after the car was manufactured, so I got no coverage from the class action lawsuit. Nice way to spend $1400 ……

        • 0 avatar
          NoGoYo

          You mean it wasn’t only 3100 and 3400 engines that got nailed with DexCool f*ckery?

          • 0 avatar
            racebeer

            Nope … the 3800s had the bigger problem because there were so many of them!!!! BTW, the LIM gasket was made of nylon with rubber o-rings surrounding the ports. You should have seen how distorted the nylon “carrier” was when it was removed ,,,, it looked like someone had taken a torch to it and just let it melt!! The new version of the gasket is aluminum.

          • 0 avatar
            DeadWeight

            Not to mention that in addition to the properties of the LIM gasket, certain GM engines had designs that allowed way too much air into the coolant reservoir, as well as other things as simple as improperly sealing radiator caps.

          • 0 avatar
            racebeer

            Very true, DW. The new coolants and air do not mix very well, to say the least.

          • 0 avatar
            CobraJet

            I wonder if the average car owner follows the manufacturer’s recommendation for coolant changes? I have seen quite a few radiators or surge tanks on other people’s cars that look like muddy water inside instead of anti-freeze.

            I just performed a coolant change on my 2007 Impala following the factory shop manual instructions. I drained the radiator and looked at the coolant. It was still orange and clear. The manual said if the coolant looked normal, just refill with the proper mixture of Dexcool. If it had looked bad, the manual instructs to completely flush the block and then refill. There is no easy way to flush the block except repeated filling with water, running the engine, then draining until nothing but clear water is left. It is impossible on this car, and I suspect many others, to get to the block drain plugs in order to completly drain the block.

          • 0 avatar
            28-Cars-Later

            Here’s my .02 cents, I drained the orange death last summer out of my 08 GP first using the AllData instructions and then two weeks later I had it drained again using a machine by the Pennzoil place while I was getting my oil changed. F*** DexCool. I can’t speak for newer GM engines as they may have been designed for use with it, but 3800 Series II came out before DexCool, it was never designed to use it (and neither was 60V6).

            @DeadWeight

            I’m not a mechanical engineer by any stretch of the imagination but if one of the engine fluids can’t tolerate contact by air very well then the fluid is complete failure and should be replaced in the design.

      • 0 avatar
        Scoutdude

        Icing is a phenomenon that occurred in the venturi of carbs heated intakes went away with the introduction of fuel injection. Yes there are coolant passages in some V engines still as that is a central location for a water outlet/thermostat housing. However the coolant passage is isolated from the intake tract take a look at the picture of the 4.6 manifold above.

  • avatar
    Zackman

    Nothing like using your customers for product testing, and not backing them up when your experiments fail.

    I suppose I could comprise a list of the “experiments” of the last almost 45 years, but we can all rattle them off, so why bother? Just don’t get caught when buying your next car and become a company’s guinea pig!

  • avatar
    jmo

    In the case of Porsche, was inspecting and replacing the plastic parts parts part of the xx,000 service?

    • 0 avatar
      chuckrs

      That assumes that the manifold wouldn’t look OK from a visual inspection. What would a bad one look like? You’d better be sitting down when they quote the cost of replacement as a cautionary measure. How can the manifold, sitting in plain sight, take so much time to replace ($3k)?
      German manufac don’t seem to be big on DFA – design for assembly. My son has an Audi Allroad with ailing turbos. To replace them, indies want $5k and dealers want $7k and most of that is labor.

      • 0 avatar
        jmo

        “You’d better be sitting down when they quote the cost of replacement as a cautionary measure.”

        If you bought a 100k car, what did you expect? It’s like buying a S class and complaining the shocks are $2k each. Well, how did you think the got the amazing ride qualiyt? Using very expensive parts.

        My only issue is they need to state this all up front. It’s like buying a car with a timing belt v. timing chain. You know you’ll have an extra 500 – 1500 expense in a few years and that’s fine. The issue would be if they try and sell you a new “life of the vehicle” timing belt that snaps at 80k miles.

        • 0 avatar
          jz78817

          “If you bought a 100k car, what did you expect? It’s like buying a S class and complaining the shocks are $2k each. Well, how did you think the got the amazing ride qualiyt? Using very expensive parts.”

          you can’t seriously believe this. a piece of molded nylon doesn’t automatically cost more because it’s for a higher-sticker-price car.

          • 0 avatar
            jmo

            They “added lightness” and as a result the car requires more maintenance.

          • 0 avatar
            chuckrs

            Didn’t they add airflow efficiency primarily? What is the cost of an aluminum manifold polished to the same smoothness as an injection molded part?

            I assumed the pictures of the manifolds were from the Cayenne – are they from the Ford? If the coolant pipes are buried in the engine compartment maybe that explains some of the cost of the Cayenne repair. But it doesn’t justify it.

          • 0 avatar
            jz78817

            the first photo is of the Cayenne V8, the second one is of the Ford 4.6 manifolds.

          • 0 avatar
            Luke42

            It’s charging what the traffic will bear. Anything else is “leaving money on table”, since the target customer finds paying extra to be a minor inconvenience.

            It’s like how the higher end the hotel, the more likely they are to nickel and dime you on WiFi and breakfast, while having roughly the same utility in most cases.

            The high end and midrange cars also have roughly the same utility.

            Given this context, I’ll leave whether or not someone who pays extra yo have and maintain an “esteem car” looks as smart as they think they do as an exercise left to the reader.

      • 0 avatar
        George B

        If the part is something that can be expected to wear out and cause catastrophic engine failure, but can’t be inspected, it should have a replacement schedule. For example, engines with timing belts have a schedule for replacing the timing belt because it’s failure can destroy the engine. I could see Porsche using nylon to save weight, but they need to schedule replacement before failure.

        • 0 avatar
          kmoney

          With the timing belt examples though you actually get (or at least before tech caught up you did get) a performance benefit in the form of reduced NVH vs a metal chain. With these coolant pipes, there is no tangible benefit to you even when they are working perfectly; it is just a case of a company cheaping out at your expense.

          Same with the S-class example. I wouldn’t be mad if my $2000 shock absorbers wore out and needed replacement; they are a wear item taking a pounding of a 5000lb car on rough roads and are needed to make the car what it is. If Mercedes cheaped out on the rear main seal and I had to drop the tranny to have it replaced every 30K then I would be mad as hell, as it’s just poor build quality for no real reason.

          • 0 avatar
            econobiker

            I still never liked the first generation Dodge Durango which had front brake brake discs only warrantied for 12,000 miles! Nicely underspec’ed for the weight of the vehicle enough to warp at about 50k. Swapped them buggers out with cross drilled aftermarket JC Whitney brand and never looked back.
            That Durango never saw me again after the discs were changed, though, since ex-wife got it in the divorce. I even sold a brand new K&N air filter and remote oil drain kit on the list of craig as to not let some punk at a quicky oil change place get the parts from my not very swift ex-wife.

  • avatar
    AMC_CJ

    Plastic pieces don’t belong on a engine, but it’s become the standard. The Jetta in our fleet has had a number of repairs done to it due to cheap plastic parts bolted to the engine failing. Garbage.

    The fact is, it’s cheaper to make. But the damn cars keep getting too expensive, and when this same cheap garbage is bolted to a engine block sitting in a $80k vehicle, it’s inexcusable. Expensive luxury cars now are a joke, made out of no better materials then something usually a 1/5th the price.

    • 0 avatar
      Zackman

      “Expensive luxury cars now are a joke, made out of no better materials then something usually a 1/5th the price.”

      Ain’t it the truth!

      Exactly why I will NEVER buy a luxury car. “Luxury” means nothing, when you can have all or most of the “luxury” features once available only on high-end vehicles on mass-market cars such as a Focus, Cruze, 200, Camry, Civic, Corolla, Accord et al.

      My Impala LTZ IS a luxury car compared to most cars only 20 years ago!

      • 0 avatar
        th009

        This is why I think “premium” is a better term than “luxury”. Features are largely electronic these days, and they move rapidly downmarket from the S-class to 5-series to Camry to Civic.

        Premium implies premium materials (at least visible materials, maybe not engine manifolds!), premium fit and finish, premium design … and premium branding (that people are willing to pay for).

        • 0 avatar
          Zackman

          Spot on!

          I have always felt that for a car to be “luxury”, or your better term “premium” means real chrome badging and interior and exterior trim, real wood, ALL leather seating with NO VINYL anywhere, real metal knobs, switches and so forth, and a minimum of visible and touchable plastic.

          Chrome bumpers would add a lot of class as well.

          • 0 avatar
            Kyree S. Williams

            The only new car I can think of that meets all of that criteria—minus the chrome bumpers—is the late-model Bentley Mulsanne…and it costs almost $300K.

          • 0 avatar
            DeadWeight

            Kyree, and even the Mulsanne is pretty much a glorified VAG under the skin of bespoke hand guided pinstriping, inlaid wood in the interior & leather trim free of imperfections caused by razor wire fencing.

            There really is no modern vehicle that’s built to the tank-like specs of a big 1980s era Mercedes Benz today.

            Whether that’s a good thing or bad thing in any particular person’s mind is the stuff of subjective opinion.

    • 0 avatar
      George B

      The way Mercedes has changed over time is sad. I do some maintenance on my girlfriend’s 1998 Mercedes E320. She doesn’t like me calling it a taxi cab, but the basic car appears to have been well engineered for long life in fleet use. It was an excellent Craigslist purchase. What’s frustrating are the “what were they thinking” engineering errors that weaken an otherwise solid car. For example, the automatic transmission is very strong. It was also used in the hemi V8 versions of the 300/Charger/Magnum/Challenger. The weakness is the E sedan puts the control electronics for the automatic directly below a flimsy afterthought cup holder. Spill your soft drink and you potentially get a very expensive repair. I can just imagine some stubborn German engineer arguing that people really shouldn’t drink beverages while they drive.

      • 0 avatar
        Dweller on the Threshold

        Mercedes has changed, that’s for sure, but they have a predilection for bone-headedness that isn’t really new.

        I’d love to hear how Jack is making out with all the vacuum operated components to his 560. Yes, those old 300Ds were tanks, but they were tanks that could drive you nuts when the vacuum lines woven throughout the chassis started to dry rot.

        Vacuum operated central door locks: no one thought the rubber tubing might not be the best approach? Anyone?

        I guess electronics have come a long way since the 70s, but Merc still was doing vacuum into the mid-90s.

        • 0 avatar
          blowfish

          Roted out vac lines can still allow u to drive the car up to hwy speed.
          Malfunction wires, micro switched can forever disabled your car to upshift to 2nd or third gear.
          Some merc’s door lock has an integral micro switch that fails can produce constantly clicking noise till u empty a whole jar of advil! And pony up the 6-700 to fix the door lock.

          An plastic intake probably takes 5 mins to make whereas an intake with alloy tubing will greatly reduce the time plus profit margin!

          Thats very much a self created problem, if u have read the manual religious or have a dealer /indie to perform all the necessary maint u will be spared from this costly repair!

    • 0 avatar
      28-Cars-Later

      Preach it brother. “Luxury” cars are a complete joke at this point.

  • avatar
    b787

    I believe exotic materials are a primary reason for such fiascos. German manufacturers are often early adopters of those materials, consequantly their reliability suffers.

    • 0 avatar
      DC Bruce

      Right about that. Just ask the owners of the BMW N52/N54 6-cylinder engines (sold in the late 1990s through the mid-2000s) who experienced catastrophic cooling system failure from either the failure of the plastic water pump impeller, the plastic radiator tank or the plastic expansion tank. These fail without warning. Experience seems to have taught everyone that 60,000 miles is the magic number; after that, just replace everything or you’re at risk of an unpleasant surprise.

      That costs about $2000 at an indie shop; about $1000 in parts if you do it yourself (including all hoses).

      • 0 avatar
        dswilly

        More like $400 for all parts (E46) and it’s a plug and play DYI. In fact it was the easiest most DFA project I ever worked on out of the last 6 cars I owned, took about 2 hours to remove all parts and replace from the water pump out. The coolant hosed are quick connect and the entire radiator assembly lifted up and out after removing 2-3 easily accessed connectors. I don’t have a problem with a coolant system overhaul at 80k as long as it’s not poorly designed to service, I’m talking to you Honda. The BMW N54’s were a very easy engine to service DYI.

      • 0 avatar
        burgersandbeer

        I think you mean M52/M54. The N series took over in the mid-2000s.

        I think 60,000 is a little conservative. It’s a good way to be sure, but I wouldn’t change it that early if you have to pay someone else.

        Waterpumps at around 100k miles are normal for most any car. They were always changed with the timing belt at this mileage when timing belts were popular. With timing chains more common, it seems like everyone forgot about the waterpump and now all of a sudden a maintenance item has become a perceived reliability issue.

        I think the expansion tanks are the really crappy parts on BMW cooling systems.

    • 0 avatar
      wsn

      “German manufacturers are often early adopters of those materials, consequantly their reliability suffers.”

      Nope. Being early adopters doesn’t necessarily result in poor reliability.

      Being early adopters AND being too arrogant to test extensively before release does.

      So much for “German Engineering”.

  • avatar
    Lythandra

    I went through the nylon fiasco with my ’03 VW GTI which I still have. I think I have replaced every plastic piece in the engine bay, unfortunately with more plastic pieces. Pain the the butt and the vast majority of them were connected to coolant. I like my old GTI alot but this plastic stuff everywhere is not made for long term ownership.

  • avatar
    ash78

    I’ll second the comments about the German marques being disproportionately reliant on materials like this. The apologist in me (for example, had you asked me about VW or Audi around the year 2000) would say “Yeah, the Germans are at the forefront of new materials. Metal is expensive and outdated!”

    Ask me today as I struggle with broken parts EVERY time I work under the hood or interior of our B5 Passats. Every service effort (DIY or professional) seems to create 2 new problems, almost always due to a plastic piece breaking.

    The realist in me say the bottom line is that modern cars are only supposed to last the length of the finance term. Case in point: “Maintenance-free” transmissions, cooling systems, etc. Further, you have issues like the nylon tubing here. And once you’re double the length finance period, as we are, the manufacturer no longer gives a crap — we are fewer than 5% of owners, but I always try to make it my mission to ensure that bad reputation items (that are FAIRLY earned) follow the marque around for an appropriate amount of time.

    • 0 avatar
      jmo

      “The realist in me say the bottom line is that modern cars are only supposed to last the length of the finance term.”

      They why do that last so much longer than they used to? It wasn’t all that long ago that having 100k miles on a car was considered a mircale.

      • 0 avatar
        Lorenzo

        Most of the 100k with no repairs cars are cheaper models with old tech, like the Corolla. There are so many sold that parts are cheap, and mechanics have seen many of them and know how to repair them. The fuel mileage and reputation for reliability keeps them on the road through several owners.

        The expensive cars with new tech take quite a hit on depreciation, but after 7-8 years they still have enough residual value to make rather expensive repairs justifiable, especially models with prestige nameplates. That keeps the CPO market for them healthy enough to keep them on the road after the warranty period. By then, it’s not a cost of repairs vs. residual value calculation, but cost of repairs vs. cost of replacement calculation.

        • 0 avatar
          wsn

          “Most of the 100k with no repairs cars are cheaper models with old tech, like the Corolla.”

          That’s just blatantly wrong.

          A very complex Lexus LS is just as, if not more, durable than a Corolla.

          The statement should be changed to “most of the 100k with no repairs cars are Toyota and Honda.”

          • 0 avatar
            87 Morgan

            Not sure this accurate. From my casual non scientific obsevation the car of choice for massive relatively problem free miles would be BOF GM, silverado, Tahoe, or Suburban. Might even throw in a Cummins Dodge to the list. I can name two off hand with 300k + on the clock of their Tahoe and Burban. Don’t know a single person with a honda at that mileage or a corolla. They all got rid of them early because the ride, road noise, penalty box feel, fill in the blank reason you can name. Quality car yes, nice place to spend 300k miles of your life, decidedly no.

        • 0 avatar
          Dan

          “Most of the 100k with no repairs cars are cheaper models with old tech, like the Corolla.”

          Corollas don’t have magnetorheological shocks or 8 different motors inside their seats. But they do have cooling systems, intake manifolds, camshaft position sensors, radios, ECUs, power window regulators, power locks, headliners, and all the other things the European makers can’t build to last either.

      • 0 avatar
        AMC_CJ

        “They why do that last so much longer than they used to? It wasn’t all that long ago that having 100k miles on a car was considered a mircale.”

        Tell that to my 78 Chevy with a 3.3L V6. 35 years old, 130,000 miles, still haven’t done a major repair to date. Of course, that depends on how you define “major” repair. Water pump, starter, radiator, fuel pump, I’ve had to replace those, bot none of that cost me over $100 in parts and a hour in labor working out of my garage.

        Give me a 100k water pump that cost $50 and takes an hour to replace vs. one that last 200k miles, cost $200, and takes a day to do.

    • 0 avatar
      danio3834

      Sure there are plenty of examples of poorly engineered components and more insteresting failure modes than ever before because of new technology and increased complexity, but cars are generally engineered to last longer than ever before nowadays. The average vehicle in the US is now over 10 years old, well past most manufacturers’ standard 3 year basic and 5 year powertrain warranty.

      Most of the car can go the long haul, so a few non fatal repairs here and there generally don’t take them out of service permanently anymore. Used to be most of the car was all used up by by 5, 7 or 10 years costing too much to keep in service.

      • 0 avatar
        jmo

        “there are plenty of examples of poorly engineered components and more insteresting failure modes than ever before because of new technology and increased complexity”

        Than ever before? It’s worse than the days of the GM 4-6-8 V8′s, diesels, Honda CVCC?

        I bring you the CVCC vacum routing diagram.

        http://images.thetruthaboutcars.com/2011/07/WOCS-Smog-500px.jpg

        • 0 avatar
          danio3834

          Oh you don’t have to remind me about all that spaghetti, I cut my teeth on trash like that. Complexity today is just a different kind, and doesn’t have as many vacuum lines.

    • 0 avatar
      ExPatBrit

      This is also partially what turned me off German cars.

      Plastic dip stick tube, parts of tube broke off and ended up in oil pan.

      $15 part, 4 hours of DIY time removing the pan and cleaning out the broken pieces.

      On the other hand looking at those test figures 5,000 hours of running time is 150,000 miles at 30 mph, so the plastic thermostat housing that failed on my Ranger at at 130,000 miles was about right.

      • 0 avatar
        DeadWeight

        That would piss me off to the point of swearing off of a brand for the rest of my life.

        It reminds me of what Jack Baruth complained of in his “Watery Big Bang” article regarding the power steering woes of his Porsche Boxster.

        I understand that vehicles are complex, and it’s not cake to design and fabricate easy to service and reliable vehicles (lest quality/reliability indexes wouldn’t be needed) but there’s just no good excuse for that.

  • avatar
    LeMansteve

    As the author states, Porsche is not the first or last manufacturer to use “plastic” components in a cooling system. It is not impossible to make a reliable hard cooling pipe from glass fiber reinforced nylon.

    It’s interesting to see the environmental and chemical effects on tensile strength. I wonder what the yield strength is. I’m active in the BMW E46 community and there are many documented failures of plastic expansion tanks (but very few failures of the plastic cooling line under the intake manifold). They usually do not see ideal operating conditions or were filled with off-brand coolant with who-knows-what additives or were simply overfilled.

    • 0 avatar
      jz78817

      I think part of the issue is that chemical degradation is something that can be difficult to develop an accelerated life test for. things like accelerated thermal cycling/thermal shock endurance tests are fairly well correlated with the real world, but when it comes to chemical interactions, not so much.

      probably one of those things were 1) they took the supplier at their word, and 2) everything seemed peachy-keen in development and testing, but when these things went out in the field and started accumulating years and miles, the flaws exposed themselves.

      • 0 avatar
        DeadWeight

        I think you are correct.

        The counterpoint, however, to what you (we) think is correct is that the Cayenne is a relatively low production unit model (at least compared to Fusions, Accords, Camrys, Impalas, Chargers, Silverados , F150s, etc.), and we’ve not heard of such high % rate of catastrophic cooling system failures (nor the litigation these spawned) regarding the latter models.

    • 0 avatar
      05lgt

      I see from the story that the testing used Zertex. Doesn’t VAG still have it’s own coolant? I remember blue crap and an oft repeated lie that “the other stuff” ate Al. Maybe that’s why VAG gets ripped on this compared to everyone else?

  • avatar
    SCE to AUX

    TTAC is that nylon isn’t the only plastic available to automotive engineers for use under the hood.

    Also, although the author has highlighted some nylon failures, many mfrs have successfully used the same grades of nylon in their products – a direct result of better engineering, not different materials.

    Nylon has been popular because it’s cheap and mold-friendly, but there are a multitude of other engineered resins that could perform better but are not used due to cost – perhaps we will see them used in greater frequency as time goes on.

    As a design engineer myself (non-automotive, however), you can be sure the car mfrs are taking into account warranty duration, terms, and the increase in leases.

  • avatar
    wsn

    To all of those defending Porsche’s failure by attributing to being an earlier adopter of technology:

    That’s just B S. Engineers should test how it works before production release. Every major car maker should have a quality control group, and they do. If there is a big failure, then it’s poor engineering.

    A Toyota Prius has more new tech than any production Porsche, and still has top durability and reliability.

    • 0 avatar
      ellomdian

      Prius tech being a Battery, a Generator/Motor, and a PDU/Controller?

      Just because it runs on magical electricity-faeries sometimes does not somehow make it an advanced supercar from the future. And it’s a cheap shot, but the 918 is a production car now :p

      • 0 avatar
        wsn

        Yes, an unprecedented battery, an unprecedented generator/motor, and an unprecedented controller. And still make money and don’t need bailout.

        Such attempts by other manufacturers are either financial disasters (EV1, Volt) or at best mediocre products that also ran.

        Oh, just to add that I have a BSc and a MSc degree in Electrical Engineering. I understand the difficulty in creating the Prius, while an un-educated (in EE) person may not understand.

        • 0 avatar
          ellomdian

          I am assuming your EE experience extends to production and supply chain economics, as the ‘difficulty’ in creating the Prius wasn’t in throwing new ‘tech’ at the problem, but utilizing a number of concurrent solutions in a packaging that a ‘normal’ person could afford?

          From an EE perspective, I would assume the Batteries and Motor are impressive. Hell, my CompSci background means I find the controller design nominally interesting. But the real magic of the Prius continues to be, nearly a decade on, pretty simple: marketing. The Volt’s biggest failing, at least from a technical perspective is also simple (and would you believe, it’s related!): It’s not a Prius.

          Also, it’s difficult to take your non-technical impression of ‘financial disasters’ in the same breath of “Don’t need bailout” – Toyota carried just over $4bn in US Debt for a quarter in 2008, and who knows how much back at home when they asked for $2bn to cover positions in 2009. Not to mention any credits and DOE Loans, those are even harder to track.

          • 0 avatar
            wsn

            The best marketing I have ever seen:

            1) “Buy American”
            2) “German Engineering”

            Both appeal to irrational buyers with no real engineering merit. Placebo for your real $$$.

            As a side note. Was Volt’s lack of sales directly caused by poor marketing? Hardly so. It’s the $40k+ price tag that killed it. For once, don’t jump to blame the marketing department. They know it will flop with such a high price. But GM’s engineering team is just weak and can’t deliver something solid with the same budget constraint as the Prius.

          • 0 avatar
            jmo

            “But the real magic of the Prius continues to be, nearly a decade on, pretty simple: marketing.”

            The most efficient and durable car on the market, that is also reasonably priced and the key is marketing?

            Seriously, you really think that?

          • 0 avatar
            pragmatic

            The Volts failure is marketing. Toyota was willing to sell Prius at a loss for a time to build sales and then make money. GM seemed intent on selling Volts at a price that insured they covered engineering costs in short order, rather than taking the long view.

      • 0 avatar
        rudiger

        Seems like it would depend on your definition of ‘advanced supercar from the future’. For many, that simply means a car with the greatest longevity and gets the best fuel mileage at an acceptable price point. In that regard, the Prius fits the bill of ‘supercar’ better than anyone else (as evidenced by sales exponentially higher than those of the closest competitor).

        And, as pointed out by commenter ‘wsn’, no one else has yet been able to successfully duplicate what Toyota has done, including when they do manage to get hold of some of Toyota’s patented controller algorithms (looking at you, Ford).

        The Prius’ traction battery and generator/motor aren’t where the ‘magical electrical faeries’ reside; they live in the Prius’ controller.

        • 0 avatar
          wsn

          Let me state my version of superior engineering:

          Given the same constraint (including cost), doing it a little better than everyone else.

          Toyota Prius certainly did it. No other car maker can match it, even when the secret formula is no longer that secret.

          Porsche? Hardly so. Are the “lower end” cars/SUVs notably better than ones offered by MB/Audi/BMW/Lexus? No. Are the “higher end” sports cars better than Ferrari/Bugatti? No, again.

    • 0 avatar
      chuckrs

      How do you properly test failures where age is a factor as well as operation? I would be surprised if any of the manufacturers did not test to high mileage, but much more surprised if that high mileage testing came at the rate of 15K miles per year.
      I still don’t like structural plastics, two words that don’t belong together.

      • 0 avatar
        05lgt

        depends on what you’re testing for. Extra thermal transients, simulated end of life abrasion, actually looking into the chemestry of what’s happening… VAG didn’t do the engineering. Maybe that’s what German engineering means to them, mistakenly applying someone elses results to a different situation.

      • 0 avatar
        wsn

        “How do you properly test failures where age is a factor as well as operation?”

        That’s why you hire someone educated to be your quality control. I don’t know the specifics of testing for car components. But in the world of computer chips, it’s been long established that increase the operation temperature has a very similar effect as “aging”. It’s an important research area all by itself.

    • 0 avatar
      krhodes1

      No, a Prius does not have more tech than a new Porsche. The Toyota HSD is actually pretty old stuff now, nearly 20 years. Any improvements have been incremental. And it is designed to be as simple and reliable as possible, as that is a major design goal. And above all that, Toyota has the deep pockets necessary to do any amount of testing that they want.

      In contrast, long-term durability simply is NOT a primary design goal of a Porsche, though overall they actually seem to do a pretty reasonable job of it compared to say Ferrari or Lamborghini. They do NOT have the deep pockets to do the sort of long-term testing that Toyota or Ford or GM do. The more complex designs mean that when something gets missed, is can cost real money to fix. You got to pay to play. I find the scale to be pretty linear – $20K cars have $500 problems, $100K cars have $2500 problems.

      If you don’t like it, don’t buy exotic cars. The makers DO learn – the cooling system in e9X BMWs are NOTHING like as problematic as the cooling system in e9xs. Though they introduced a new issue with the electric water pump, which is certainly fairly bleeding edge tech in the auto world. But even there, there have been several revisions over the course of the e9X’ life, and the latest ones do seem to be lasting a lot longer on average. Time will tell.

      • 0 avatar
        krhodes1

        Oops – I meant e9xs are not as problematic as e46s.

      • 0 avatar
        Kyree S. Williams

        I don’t know. I’m kind of afraid of BMW turbos still, so I’d stay away from mid or top-level E90s, but a 328i—with of course the naturally-aspirated 3.0-liter I6—sounds promising. A 2009 (for the sedan or wagon) or 2011 (for the coupe and cabriolet) would be ideal, so that I’d have the LCI styling updates.

        • 0 avatar
          krhodes1

          I would not be “afraid” of a turbo BMW vs. a non-turbo. You simply have to have reasonable expectations. Ultimately, a turbo IS a wear part, just like a water pump. It WILL have to be replaced eventually. It DOES increase the stress on other components if the potential power is used on a regular basis. No free lunch.

          Given the choice between the 230hp non-turbo and the 300hp turbo, I too would choose the non-turbo (I kind of did). But I would have picked a ~200hp turbo 4 over either one, given the choice.

  • avatar
    jz78817

    cripes, I just noticed something: did Porsche bury the starter inside the vee also?

    • 0 avatar
      stuart

      Regarding the first picture:

      Yes, that is obviously the starter. I’ve never worked on a Porsche V-engine, but the intake manifold has been removed, and the intake ports on both heads have been covered with tape (looks like duct tape). There is a screwdriver lying on top of the tape applied to one head.

      The leftmost of the original three nylon coolant pipes has been removed, making the starter more visible.

      stuart

    • 0 avatar
      natsogood

      Yep, the starter sits right at the bottom of the bay. When I removed the plastic pipes I found it bathing in a puddle of coolant. I really didn’t want to pour more money into the project so I decided against replacing it; almost a year later, knock on wood, it works just fine

    • 0 avatar
      danio3834

      Looks like it. Other notable engines that did this were the Cadillac Northstar and Toyota UZ V8.

  • avatar
    DeadWeight

    This is a fantastic article, a great way for TTAC to kick off the New Year, and hopefully we’ll see a lot more articles of a technical nature, where engineers, material scientists, and others with specific technical backgrounds can both write articles and be lured into commenting as part of the B&B.

    Regarding this article, it is timely especially because of the rate of change that’s happened in the composition of coolants in the last decade. While many will find this hard to believe, color of coolant no longer means anything, simple Propylene Glycol Antifreeze of the old silicate type (the “green stuff” that had to be changed every 2 years) is withering away, and NEARLY ALL manufacturers now factory fill (on the assembly line) their vehicles they produce with what is essentially Dexcool, whether a Organic Acid Technology (OAT), Hybrid Organic Acid Technology (HOAT), Poly Organic Acid Technology (POAT) variety, that use any number of a variety of acids (2-EHA, Sebacic Acid, etc.).

    Silicates and phosphates are not included in OAT types of antifreeze.

    Hybrid OAT (HOAT) formulations are hybrid because additive packages contain ingredients from newer OAT ethylene glycol antifreeze types and the conventional ethylene glycol green formulas with nitrites added.

    Confused unless you’re a chemist (I’m certainly not a chemist)? Yeah. I won’t even get into Nitrated Organic Acid Technology (NOAT), Nitrite Molybdate Organic Acid Technology (NMOAT), etc.

    The basic point is that there really are only Dexcool or variations of Dexcool such as HOAT (i.e. may have a very low level of silicates and phospates in the additive package) that are now being used as factory fill coolants in 95%+ of ALL vehicles, including Chrysler/Fiat (which uses HOAT), Ford (which now uses essentially straight up Dexcool), and ASIAN or German ones, despite the shear indignation of their owners (but, but…my Toyota/Honda/Subaru/Nissan/BMW/Mercedes/Audi/VW coolant is pink/orange/blue/rainbow colored).

    So with regard to this article, the primary claim is that it is the organic acid additive, included in the coolant in the first place to prevent oxidation of the coolant system’s metals and to prevent “sludging,” that is attacking and weakening the chemicals that companies such as Dupont have used to “coat” the nylon and short glass fibers that are used in coolant system components, so as to make them of a far higher tensile strength (at least when new, and as test in a low humidity, controlled environment).

    If this is closer to true than not (and although far from an engineer or scientist, my silly sense of what’s common tells me it is closer than not to true), it would at least suggest that the rush to replace metals in cooling system components with chemically treated nylon/glass molded ones nearly COINCIDED with the rollout of organic acid type coolants (that I refer to in the most general terms, whether OAT, HOAT or POAT, as Dexcools).

    We need more articles such as this.

    • 0 avatar
      bill h.

      Agree, more articles of this type!
      BTW, you mention the old silicate containing “green” stuff as being propylene glycol–IIRC the “anti-freeze” active ingredient in those conventional coolants was also ethylene glycol. I have seen non-toxic coolants made with propylene glycol on auto parts store shelves in years past, but have no idea of how well they performed.

      • 0 avatar
        DeadWeight

        I think you’re correct and stand corrected.

        I believe that whether the base is PG or EG, that component keeps the coolant from freezing, while the water component transfers the heat, and the silicates coat the metal internals of the coolant system with an oxidation-preventative “blanket” (which is why the white scaly buildup in old school coolants will eventually clog/kill water pumps if not changed out’every 2 years).

        I’ve personally had really good luck with extended life Dexcool-esque coolants, regardless as to what particular acid they contain, but I do know of several family members and friends who had problems with Dexcool in particular GM vehicles with the 3.4 liter, 4.3 liter (? I think it was a 4.3) and even the usually rock solid 3.8 3800 Series (although that was the result of user error in mixing Dexcool and non-Dexcool).

    • 0 avatar
      Kyree S. Williams

      If you have this kind of understanding—because I had no idea that coolant was so complex—perhaps you should be one of the TTAC story contributors. In-depth knowledge like this is always fascinating.

      • 0 avatar
        DeadWeight

        I don’t think I’m qualified to render an opinion on it. I honestly believe one has to be a competent scientist with a background in chemical engineering to truly be qualified to speak to the ever growing complexity of coolants & coolant systems.

        The one thing that fascinates me more than anything regarding this topic is what % of catastrophic motor failures are actually attributable to coolant system woes, yet never realized/acknowledged as such. My curiosity about this began when I NEARLY bought a Cadillac DTS with the 4.6 Liter Northstar for a family member, and then learned about how that motor, being of a partial aluminum makeup, was highly susceptible to catastrophic issues if run in an overheated state (part and parcel of the head bolt “backing out” issue).

    • 0 avatar
      pragmatic

      Reminds me of the failures in early plastic pipes used in housing. The stuff would last, but the Chlorine used by water systems for disinfectant weakened the plastic and caused failures several years (not many) after install. After the lawsuits they re-engineered the material to take in account the chlorine in the water.

  • avatar
    Felix Hoenikker

    When it comes to chemical compatibility, testing is everything. But, as mentioned before, the tests must simulate the real word use of the material. In my first job as a newly minted chemical engineer, I worked on a project to chemically separate oxygen from air using molten salt mixtures. Both the thermodynamics of the oxygen adsorption and desorption reaction were tested to confirm the design.
    The material compatibility testing also indicated the the molten salt mixture would not corrode the stainiless steel alloys to any singnificant degree. We built a pilot scale unit to demonstate the technology. After a few hours of operation, things started going very wrong, and the unit was taken out of service. Upon inspection the pump was found to have no impeller left, and one of the wedge shaped flow meters was missing the internal wedge. In fact everywhere there was turbulence was accompanied by severe corrosion.
    We found the cause of the extreme corrosion was a super oxide generated in small quantities during the process. It did not show up in corrosion testing because the metals reacted with the samll amount of the compound, but it was not regenerated like in the actual process. The testing results hid the actual corrosion caused by the super oxide because the super oxide was present in low concentrations and completly consumed in the test. It was an expensive lesson and killded the project.

    • 0 avatar
      DeadWeight

      Thanks.

      There’s a thread on rx8club that gets into all of this, and thus far has concluded (rightly or wrongly) with the opinion of a chemist that the acid additives are pretty much all equally destructive because of the fact that chlorine is present is copious amounts in nearly everybody’s coolant, and chlorine is a catalyst of any acid (be it carboxylic acid, sebacic acid, 2-EHA, etc.), especially AT high temperature.

      Posts 61, 74(Peak Global may be straight up Dexcool) and 91 are especially good. I still don’t understand this stuff pretty much consistent with what the OP of this thread admits even after “experts” chime in:

      http://www.rx8club.com/series-i-tech-garage-22/issue-many-ignoring-most-coolants-contain-2-eha-eats-silicone-238638/page3/

      • 0 avatar
        DeadWeight

        Felix, I forgot to ask you if you think that a simple ph type test (chem strip or other) measuring alkalinity or acidity would be useful to determine how “aggressive” the acid additive package in one’s coolant has become?

        Thanks.

      • 0 avatar
        Manic

        BASF, the biggest chem. co. there is, has this site which explains a bit about coolants they sell to car OEMs and service industry and also about cooling systems, there’s up to 100 different materials in system and liquid should play ball with every one of these.

        http://www.glysantin.com/20-1-Engine-coolants-Know-how.html

        “On average, engine coolants have to undergo thirty different tests before they are approved by motor manufacturers. These mainly consist of various different corrosion and compatibility tests with the original components of the cooling system. Motor manufacturers do not give official approval to coolants until they have passed all the tests. The process takes three to five years and it is very expensive. The coolant has to go through the entire approvals procedure again every time a change is made to the formulation. ” – and still, there’s stories like that Porsche situation…

  • avatar
    stuart

    Fabulous article; more please!

    stuart

  • avatar
    ajla

    Every vehicle manufacturer is terrible.

    • 0 avatar
      DeadWeight

      Except for Lincoln in 1961, GM in 1968, Volvo in 1966, Honda in 1994, etc.

      ;-)

    • 0 avatar
      Dweller on the Threshold

      The thing is, the more esoteric cars get the more they’re just toys.

      A Corolla may be designed and sold as a durable good (and maybe not), but no one should think that is Porsche’s goal.

      Various Swiss watch companies have had terrible reliability (design defects, manufacturing defects, etc.) along with awful customer service. No one really cares, and this seems to be a pretty minimal drag on the reputation of the companies (and, I would assume, their profits).

      At a certain point, a very expensive car is just a great big analogue to a Swiss watch.

      • 0 avatar
        krhodes1

        Of course. Why would anyone think of them any other way? A lot of people have very ridiculous expectations.

        • 0 avatar
          Dweller on the Threshold

          Well, at least Porsche is doing its part to clarify expectations.

          Mine have been made much clearer by the IMS semi-scandal, since I missed out on the exploding air boxes of yore.

        • 0 avatar
          ajla

          “Why would anyone think of them any other way? A lot of people have very ridiculous expectations.”

          What are the proper expectations for a person that purchases a $55K Macan or Boxster?

          We aren’t talking about exotic supercars built for the mega-rich and racers here. This lawsuit was about the Cayenne.

          If Porsche wants to sell in higher volume and closer to the mainstream, then I don’t think it is unreasonable for those vehicles to have more mainstream expectations.

          • 0 avatar
            Dweller on the Threshold

            “If Porsche wants to sell in higher volume and closer to the mainstream,”

            Whoa there!

            Profit is the key. That is all.

          • 0 avatar
            ajla

            “Profit is the key. That is all.”

            If the way they are hoping to increase profit is through higher volume, moving into mainstream market segments, and having lower price levels, then my point still stands.

            The expectations of someone that buys a 918 or GT3 is going to be different from someone that buys a Macan. I hope that Porsche and their supporters understand that, and I don’t think it is unreasonable for that expectation gap to exist.

  • avatar
    jacob_coulter

    I’ll just never trust composites/plastics if it’s an important part. Period.

    How many times have we been told “this time we’ve got it right” only to see it once again fail? Remember polybutylene pipes? How many houses were flooded from that “technology”?

    Whether it’s plumbing, automotive parts,structural pieces, etc. It seems it always ends up crumbling to pieces. I could understand this if we were still in the infancy of composite manufacturing, but even in the late 90′s, “experts” were still falling flat on their faces with their “high-tech” substitutes.

    • 0 avatar
      redmondjp

      As an engineer who formerly though of plastic parts as being low-quality, I have begrudgingly come to see how wrong I was. But as we are seeing by this example (in the ‘death valley’ of a V-8 engine), there are still places where plastic parts don’t hold up well.

      For homes, plastic drain piping (ABS & PVC) has a proven track record, but it wouldn’t surprise me to see PEX piping listed on home inspectors’ checklists in another 20 years. Time will tell!

    • 0 avatar
      jz78817

      “I’ll just never trust composites/plastics if it’s an important part. Period.”

      people used to say the same about aluminum.

  • avatar
    Kyree S. Williams

    Not that I’m against the idea of buying a Porsche, but long-term durability is just not that company’s focus. The fact that the Cayenne is a CUV that sees plenty of family use does not mean that will inherently have the reliability of a Lexus RX. The Cayenne is, above all, an expensive five-seater toy, designed to deliver an exclusive and world-class experience for a short amount of time…and if you go into the purchase process knowing that, it’s not such a surprise when things happen.

    By the way, was this an issue on the 4.5-liter V8 or the 4.8-liter V8…or both?

    • 0 avatar
      ajla

      “… designed to deliver an exclusive and world-class experience”

      Then I would argue it fails miserably at that. I thought the whole idea behind the Cayenne was to “make money” so Porsche could keep building sports cars and exotics.

      Seriously, what is exclusive or world-class about all but (maybe) the most expensive examples of the Cayenne?

      • 0 avatar
        krhodes1

        Well, it is MUCH faster even in the basic versions while also being capable of being flung around corners a lot harder, stops shorter, has some actual off-road capability (allegedly) and is generally a much higher performance vehicle than something like a Lexus RX. Which is fundamentally a jacked up Camry station wagon with a niceish interior. The Porsche will last just as long, it will just cost more along the way, just like it cost a lot more up front.

  • avatar
    schmitt trigger

    Dead Weight;
    you may not be a chemist, but your understanding of engine coolants is light years away from knowledge! This article and your comments enlightened me and shortened that gap…thanks.

    I’m a EE who specializes in failure analysis for transportation products. I can tell you that in the last 3 years we are seeing a significant increase in electronic component failures due to chemical attack.
    The conclusion I’ve personally arrived to is that technology has become significantly more complex, but, the actual selling price has not kept pace with the increased performance.

    • 0 avatar
      DeadWeight

      Thank you for the high praise, whether I deserve it or not.

      I have begun to appreciate how vast the difference is between testing in a lab, and testing in the real world, given the hundreds or thousands of variables and combinations of variables in the real world that can’t be necessarily anticipated, let alone controlled for, in the lab setting.

      I believe that this is the fundamental challenge faced by all who seek to predict outcomes based on the results of testing “things” in a laboratory setting.

  • avatar
    jeffzekas

    Virtually every part that broke on my son’s BMW was a plastic part. This tells me: plastic is not ready for prime time. Unfortunately, there is always some sucker who will buy a BMW without first going to the owner sites and doing research. And of course, the fanboys spread disinformation about how “wonderful” their Bavarian junk is, now “reliable”, how well made… suckers.

  • avatar
    carrya1911

    Articles attempting to have an intelligent discussion on engineering are most welcome. Keep it up.

  • avatar
    87 Morgan

    I would also like to concur with those who have indicated a desire to see more articles liked this on TTAC. I find it quite fascinating.


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