By on April 23, 2012

 

TTAC Commentator edgett writes:

Sajeev –

I’ve got a 2007 BMW 335 which has a direct injection system. Although I enjoy the car, it has been through three fuel pumps in 35,000 miles and BMW has thankfully extended the warranty on the fuel pump to 100,000 miles and seven years. The benefits, however, are extraordinary. This engine gets excellent fuel mileage and makes fantastic power. So tell me why DI systems are so difficult that mighty Honda has yet to take the plunge!

Sajeev answers:

Actually they are jumpin’ on the bandwagon. And I am totally okay with auto makers taking far too long (for some people) to get their act together, but that’s a byproduct of being a Lincoln-Mercury fanboi used to such disappointment.  Anything, like the recent news from Honda, that gives me a glimmer of hope gets my heart all a-flutter!

Could be worse, I could be a Pontiac fanboi. But I digress…

Automakers have finite resources.  They may not put all their eggs in one hand basket, but they will stick with something for a soon-to-be made product to give it the best chance of success. That’s just smart business.  Imagine how bad it would be for Lincoln if they didn’t promote Ecoboost stuff, instead focusing on the next generation Town Car with a Coyote V8!  Oh wait, there I go again. Dammit.

Keeping corporate news releases and press exposure to one item is fair, but when it comes to R&D and pie-in-the-sky products, everyone hedges their bets. To some extent. Hyundai was the first to go mainstream family sedan with DI motors, obviously they were ahead of the curve and everyone else decided to make sure their stuff was at least as reliable.  And there’s a good chance Hyundai learned something from BMW’s fuel pump issue. Honda is following Hyundai, for all the right reasons.

Money. Time. Resources.  External human influences.  The wrath of Mother Nature. All of these hold back Honda’s DI motors…and occasionally break the heart of a Lincoln-Mercury fanboi.

Believe that.

Send your queries to [email protected]. Spare no details and ask for a speedy resolution if you’re in a hurry.

 

 

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44 Comments on “Piston Slap: D.I. Another Day?...”


  • avatar
    don1967

    “And there’s a good chance Hyundai learned something from BMW’s fuel pump issue. Honda is following Hyundai, for all the right reasons.”

    If Hyundai learned from BMW, and as a result its DI systems are proving reliable, what exactly are Honda’s “right reasons” for sitting on the sidelines? Wasn’t Honda the company that used to bring new technology – like multivalve engines or variable valve timing – to the mainstream first?

  • avatar
    hreardon

    I have to say, DI has been a mixed bag, but if the automakers are willing to stand behind this relatively new technology and make incremental improvements, I’ll deal with it. As in BMW’s case, Audi has applied an extended warranty on their first generation FSI motor due to its proclivity for chewing through cam followers and intake camshafts and the HPFP after that. Audi has had significant growing pains with their 2.0T – fuel pumps, carbon build-up, failing diverter valves, a PCV that has been redesigned at least four times in the 4 years the original was on the market, etc. etc.

    That said, the second generation TFSI engine that debuted in 2008.5 corrected nearly all of the faults of the original and from reports, is pretty damned bulletproof assuming you change the oil every 5,000-7,500 miles.

    This is a technology with significant legs, but signifiacnt room for overall improvement. Apparently Audi’s third generation direct injected system has picked up on the carbon buildup issue and will implement a two-phase system to help ‘wash’ the valves to reduce the buildup.

    But I agree – the benefits of DI are substantial.

  • avatar
    supersleuth

    If at all possible, I just won’t buy a car with a DI engine until I see a lot of them going 200,000 miles + without any more significant issues than I’d expect from a good port-injected engine. Hondas already get highly competitive fuel economy; I wish they’d been even slower in following this trend and I hope it doesn’t trickle down to the Civic and Fit for a few more years.

    • 0 avatar
      jz78817

      “If at all possible, I just won’t buy a car with a DI engine until I see a lot of them going 200,000 miles + without any more significant issues than I’d expect from a good port-injected engine. ”

      diesels seem to have managed with DI for about 100 years.

      • 0 avatar
        supersleuth

        Correcting what I wrote earlier: Diesels in the past have had a lot of fouling issues, but these seem to be dealt with pretty well in contemporary engines; I’m sure that will happen with GDIs as well, but I’d just like to see a track record before laying out my money. (However, fuel pumps have been a continuing issue in VW TDIs.)

      • 0 avatar
        jz78817

        http://www.autoobserver.com/2011/06/direct-injection-fouls-some-early-adopters.html

        supposedly GM and Ford are claiming they don’t have a severe problem with deposits. The only stuff I found on a quick search for ecoboost valve deposits was some company who conveniently sells products for cleaning valve deposits.

        maybe we’ll have to wait and see after more of these engines get real-world miles on them.

      • 0 avatar
        supersleuth

        Doesn’t Hyundai currently recommend frequent use of fuel additives for its cars with GDI? That doesn’t seem like a sign of confidence that the deposit problems have been overcome, at least by them.

      • 0 avatar
        redmondjp

        Supersleuth,

        Diesels have not been direct-injected for 100 years, that has only occurred in the past 25 years or so. Before that, the injector sprayed into a precombustion chamber where the glow plug is located. Direct injection pumps usually operate at a higher pressure than the older IDI ones.

        My 1981 VW Rabbit 1.6l diesel was indirect injected, while my 1996 Passat 1.6l TDI is direct-injected.

        Ford started using the “Powerstroke” name when they switched from indirect to direct injection on the 7.3l International diesel in 1994.

      • 0 avatar
        jz78817

        redmondjp,

        diesels have been used in far more than cars, and diesel engines overall have been direct injection for a long damn time. prechambers were a passing fad to try to quiet them down and clean them up some, but the tradeoff was that they tended to need much higher compression ratios and had poorer efficiency due to heat loss. electronic controls and high-pressure multi-shot injection has made DI feasible again.

        besides, we’re comparing to port injection, so an IDI diesel is still “direct injected” as much as it matters in this discussion.

  • avatar
    NormSV650

    Time to give credit where credit is due as GM has been using DI since 2006 or half decade now. But it was used in 2.0l Turbo when equipped with GM performance tune made 290 HP and around 330 torque, bettering all normally aspirated Toyota/Honda V6’s.

    GM DI started in a turbo engine which like the cooler fuel charge some Toyota/Honda do not have.

    Should discuss multi-speed tranmissions that Toyota/Honda doesn’t have also? Anything Japanese fanboi’s like to gloss over because the manufacturers have been resting on their deflated Japaese bubbles the last two years in Honda was No. 1 in recalls last year and Toyota the year before.

    I understand the cost of jumping ship, but what are you current Toyota/Honda owners going to buy next?

    • 0 avatar
      CJinSD

      I’m refreshing the fleet with new Hondas before they let marketing make their engineering decisions. Took delivery of a 2012 CR-V EX-L AWD last Thursday. Port injected, chain driven DOHC, naturally aspirated 4 cylinder with a 5 speed automatic. Whatever ridiculous policies the suicide regime enacts, I’ll have another vehicle without a built in expiration date to go with the TSX and Civic Si, all K-series NA powered and paid for. In contrast, the 2012 Audi A6 with supercharging and direct injection is a lease that will be someone else’s problem in 37,000 more miles.

      Listing the claimed output of a chipped turbo engine may be a new superlative in the field of lame. What are the Saab lemmings going to buy now that the market has spoken and you’ve been pronounced the weakest link?

    • 0 avatar
      albert

      Hmmmmm… GM introduced the 2.2 liter L850 with DI in Europe in 2003.
      But was it without problems?
      Ask the Opel/Vauxhall dealers on the number of fuel pumps used and you know.
      In fact, the ADAC chose this engine to show what can happen if your car cannot use E10 (gasoline with 10% ethanol). The result: it eats even more fuel pumps.

    • 0 avatar
      chrishs2000

      Where are all of these “Japanese fanbois” you’re ranting about? Nice straw man argument, I don’t see any posts like that in here.

      And GM/Ford can keep their terrible 6-speed automatics that are tuned explicitly for the purpose of the EPA city cycle test. I recently drove a 2012 Mustang V6 auto for a week and the transmission absolutely kills that car. Feels like the gas pedal is linked to the throttle body via a linkage made entirely of mashed potatoes. Same with all the other GM/Ford 6AT’s I’ve driven in the last couple of years. Great gas mileage, but my wife’s 5AT Accord actually feels sportier than the Mustang due to a transmission that shifts firmly and corresponds to the throttle input instead of completely ignoring it and grabbing the highest gear possible.

  • avatar
    redav

    I was just wondering how the fuel pump for a DI engine is any different than a traditional engine.

    Speaking of DI reliability, are there any trends of failure that are DI-specific? People are apt to point out theoretical failures for DIs, but I don’t know if any have actually been occuring.

    • 0 avatar
      supersleuth

      “I was just wondering how the fuel pump for a DI engine is any different than a traditional engine.” Much higher pressure.

    • 0 avatar
      jz78817

      it’s similar to the pump in a common rail diesel engine, but not nearly as high pressure. Port injection systems run at about 40-60 psi, DI gas systems are around 1500 psi, and DI common-rail diesel systems can be up to 20,000 psi if not higher.

    • 0 avatar
      Ubermensch

      There is a long history of failed HPFPs in BMWs and other brands. There have also been issues with carbon buildup on valves. These aren’t theoretical, they are happening quite regularly especially with the BMW HPFPs.

      • 0 avatar
        dave504

        BMW has been through six(!) different designs for their DI N54 engines, and still cannot get a handle on fuel pump failures. All VW/Audi FSI engines have carbon/sludging issues, and even the Hyundai GDI is experiencing carbon problems (users in some forums are even now recommending catch cans). I find it funny that people are recommending high-quality gas and seafoam as treatments – they must not know how direct injection works.

  • avatar
    captnslur

    Edgett, your motoring expectations are very low, sir.

    You say your 335 gets “excellent” fuel mileage – at 20 MPG combined on premium, that’s medeocre at best and replacing three feue pumps in 35,000 miles is quite unreliable. How many times were you stranded with this BMW?

    The new performance is efficientcy and 50 MPG is “excellent” mileage, not 20 MPG. Perhaps you need to upgrade your ride.

    • 0 avatar

      Sorry to be late to this party, but I was out of the country. The “excellent” fuel mileage I cited amounts to 20 in around-town short-haul mixed driving and a measured 27 in an 1100 mile highway trip which included a number of trips into triple-digit territory. For a car which weighs over 3600 pounds, meets modern crash criteria and yet will still hit 60 in about five seconds, this kind of fuel mileage is remarkable.

      While I won’t tout the reliability of three fuel pumps over 35,000 miles, they were replaced in routine service visits and did not involve stranding.

      As to upgrading my ride, my car choice was based on the best criteria available when I made the purchase and I am an unashamed fan of the “feel” which BMW imparts to their small sedans. The in-line six makes all the right sounds and my previous BMW would make track visits without causing significant pain (the 335 goes to limp mode far too readily for my taste).

  • avatar
    gtemnykh

    Unlike other manufacturers, I think Honda was hesistant to release a half-baked technology just to be ‘cutting edge.’ See Audi’s problems with intake valve carbon build-up and Hyundai’s insistence on a bottle of fuel injector cleaner every 7.5k. Even without DI or a 6 speed transmission, the Civic doesn’t just match other manufacturer’s EPA ratings, but exceeds them in real world driving. I’m going to be in the market for a new car (graduating, have job offer), and I was shocked at how people dismissed the 9th gen Civic as lagging behind the competition. Reading into the issue, I’d say the Civic is very much in the fray for top honors in the compact class. Another example is the ancient Corolla with a 4spd auto that gets real world fuel economy that’s pretty much equal to the elantra with its 6spd, and better in the real world than the porky Cruze.

    The camry with its new 2.5 I-4 (port injected) matches the super-sleek and DI-equipped Sonata (both have new 6spd autos). The fact that Toyota can engineer an engine using tried and tested tech that Hyundai has to employ DI and a super slick drag coefficient to match shows me just how competent Toyota’s engine designs are.

    While they may have been eclipsed in soft-feeling dashboards, the engineering know-how of the Japanese is still a force to be reckoned with.

    EDIT: To give credit where it is due, GM doesn’t seem to be having problems with their DI systems, which as another poster noted, have been around for a while now.

    • 0 avatar
      NormSV650

      Nice Japanese Kool-aid and domestic manufacturing bashing. That’s an old drink you have there. Did you need a refresher or some ice to bring your thought process out of the mid-2000’s?

      • 0 avatar
        chrishs2000

        Sorry, but he’s mostly right.

        Honda is very reluctant to embrace technologies that they do not perceive as 100% reliable. There are many technical papers published by Honda relating to DI in the last 10 years; it is obviously a well known and studied technology to them. They actually have had a DI engine available in Japan for several years. However, they simply have not seen the advantage that offsets the cost and durability concerns of a full DI engine lineup. They feel that port injection has capabilities that have not been fully exploited and that DI will be a passing fad – this is my second hand understanding from those who work at Honda. Whether or not it is true remains to be seen, but it seems that for now Honda is going the DI route. I suspect that their fuel delivery system and tuning will be substantially different than the others.

        GM has done a tremendous job of tuning its DI system to have very few issues in production. But they are pretty much alone, as all of the others have not – BMW’s HPFP failures, Audi’s severe carbon build up issues, etc etc etc.

      • 0 avatar
        moedaman

        Seems to me that he’s bashing the Koreans more than the domestic manufacturers. He doesn’t mention Ford and he even praises GM at the end (and the Cruze is porky). The Civic with an older engine and 5 speed auto does get EPA milage that’s as good as anyone else. Not the best, but far from the worst. 28/39 is pretty good don’t you think?

      • 0 avatar
        jz78817

        Honda hasn’t done much of anything with their cars in the last 10 years. I’m not sure they’re the best example.

      • 0 avatar
        gtemnykh

        I was considering a Ford Fusion or new Focus, then a look at forums scared me away pretty quickly. The Fusion’s 6F35 6speed transmission has had a number of reflashes released, with people still having problems with flaring between shifts, apparently the issue is with a valve bore made out of aluminum that wears excessively. The redesigned Focus has abysmal rear legroom (as does the Cruze), both are worse than their predecessors in this regard. The Focus’s new dual clutch automatic is also extremely suspect judging by reviews and forums. I’m actually looking forward to test driving a 2011 vintage Focus, the pre-redesign one, they had all of the problems worked out (since it is basically a rehashed 1st gen from 2000), get great mpg, are quiet, comfortable, and roomier than the new ones.

        It’s a shame because I actually love the way American cars feel and drive, they are quiet on the highway and always have ice cold A/C. I’ve been in two rental Impalas that I really enjoyed except that both had minor mechanical issues at negligible mileage (leaky exhaust, A/C condensate dumping onto passenger’s feet). Likewise I think the Fusion’s interior is fanstastic, very quiet and better padding on ‘touch’ points than the accord or even the 2012 camry. But it seems too often that the buyer is treated as a guinea pig on early model year cars with.

        My father has a 2007 Fit Base manual. No mechanical issues to speak of, but it has a dash rattle and the seat is unbearable on long trips. I don’t make any excuses for the car, I call it like I see it. I myself drive a 1998 Mazda MPV with 145k miles on it. It’s had a fair share of small niggly repairs that I’ve done myself, many of them are awfully expensive due to the rarity of replacement parts (try e-brake cabes for $100+ per side!). It also gets 15mpg around town while being extremely underpowered. I don’t think Japanese cars are the end-all be all of automotive design, but out of the current offerings, if I have to put my money where my mouth is, I’d bet on a Civic/Corolla delivering better mpg and lower operating costs than a Cruze, Focus, or Elantra.

      • 0 avatar
        golden2husky

        chriss2000 is totally correct. Honda is used to introducing new technology when they feel it is proven. They made the bet that is was not ready for Honda levels of reliability. GM did there homework here; they seemed to have engineered out the vast majority of the problems. Let’s hope the bean counters don’t decide to take three bucks out of the HPFP and then ruin it all…

    • 0 avatar
      rgil627il

      off yourself please. Cretin.

  • avatar
    stuntmonkey

    Development is like spending skill points in your favourite RPG game, you only have a limited number of points to go around. Over the past two generations, Hyundai went with with DI and improved manufacturing, VW went with DI and DSG, BMW went with DI and turbos. Honda went with hybrids and a a lot of little things that aren’t hit you-over-the-head spec-sheety, like cylinder deactivation, cracked con-rods and molybdenum coatings. You can argue that IMA is a dead end on the skill point tree.

    If you string together all a good implementation, a DI motor has consistent advantages over standard injection. But ignoring the cooling effect and bump on torque that DI has, there are a lot of ways that standard injection engines today make up for the difference at part throttle.

    With Honda you have the two stage econo-vtec of the Civic where only one valve gets opened at low speed, or the pseudo-Atkinson cycle of the Prius where the intake stroke is effectively shortened by holding the intake vales open. Cars with electronic throttles tend to open the throttle wider than indicated during acceleration to reduce pumping losses.

    And really, DI is just one component in the whole equation. You can make one improvement on the engine and lose it in the drive train. I think that we’re at the stage where an older conventional injection engine with a five speed can match a newer DI engine with six if the implementation is done right, but going forward, DI with six speeds will be the way to go.

    • 0 avatar
      chrishs2000

      Honda went with IMA for two reasons: They did not want to infringe existing patents like Toyota knowingly did with their system (and get sued like Toyota did), and they did not believe that battery technology would advance as repidly as it has. I would agree that 10 years after the Insight debuted, it’s pretty much a dead end. This is why they are changing directions with EV’s and the newest generation of IMA.

      I believe that we are on the precipice of some pretty groundbreaking port injection combustion technologies far superior to DI systems enabled by today’s controls that will allow cars to run efficiently with super lean AFR at part load with the same or better HC/CO/NOX emissions…I expect that in 5-7 years years we will begin seeing these strategies employed in engines with an immediate 20-30% bump in fuel economy at cruising speed without downsizing or sacrificing power at full load. Whoever gets there first without the extreme cost of DI/downsizing will have a huge advantage.

  • avatar
    Dan

    “The benefits, however, are extraordinary. ”

    The benefits are a few percent better power and fuel economy. DI is an exceedingly expensive way of achieving the former, and 1 mpg is a distinction without difference for consumer applications.

    Like 9 speed transmissions, TPMS, four O2 sensors, etc., DI is primarily an answer to lawmaker stupidity.

    • 0 avatar
      carguy

      Dan – I would disagree. The combination of DI and forced induction are a major step forward in engine technology. It allows an a nearly 4000lb 528 sedan to get 32 highway MPGs and still make the run to 60 in the 6-7 second range.

      This is the reason why both Ford and GM are investing in it.

      And its not just because of the Government – oil is getting expensive and consumers are demanding better fuel economy without sacrificing performance.

    • 0 avatar
      N8iveVA

      I wouldn’t exactly call a 5% increase in fuel economy and anywhere from 15% to 30% increase in horsepower to be “a few percent better”

      • 0 avatar
        chrishs2000

        30%?!? Where does this magical number come from?? Maybe in conjunction with downsizing (e.g. turbo), but certainly not from DI alone. 5-10% bump in peak power seems to be the norm for DI systems compared to well tuned PFI examples.

      • 0 avatar
        Moparman426W

        I remember reading an article a couple of years ago in Popular Hodrodding, they showed the workings of the coyote engine and interviewed a Ford engineer. DI was brought up and the engineer said that DI in itself only results in a one percent improvement in power and mileage on a naturally aspirated gasoline engine.

      • 0 avatar
        N8iveVA

        chrishs2000 – I’ll use the new Genesis coupe as an example, the 3.8L V6 went from 306 to 348 hp with DI. Basically a 14% if my math is right. And yes the 30% i threw out there was for the 2.0L turbo that went from 210 to 274 hp. But in all fairness they also went from a single to a twin scroll turbo, so the DI alone didn’t add all of the increase.

        Moparman – just wait and see, i bet when they add DI to the 5.0L Coyote you’ll see at least a 30hp increase

  • avatar
    tedward

    Personally I only recommend DI to people who want a modern fast car, or who have a history already with turbocharged cars or european V-8s. They certainly aren’t guaranteed to have problems, even with the fuel pumps, but it’s a chance any buyer is taking if they treat their vehicle as a casual purchase. A realistic hobbyist, or a buyer with someone in the family who makes sure that there car gets seasonal, as well as recommended and preventitive, maintenance could buy one of these feeling fairly confident.

    FWIW almost all the real horror stories I’ve heard so far have come from BMW owners.

    In response to one of the questions above…gasoline direct injection engines are running VERY high fuel pressure while diesels are running even higher. They gain fine control of combustion, but make slightly more noise and tend to the abovementioned fuel pump and carbon buildup issues. I’d bet on DI getting reliable really fast, it may actually be there already now that some manufacturers are past their first generation DI offerings.

  • avatar
    nikita

    While any new technology has growing pains, and modern consumers are much less tolerant of problems than in the past, DI gasoline will become commonplace soon, just as sequential port injection did.

    One of the most basic ways to get more power and efficiency from an Otto cycle engine is to raise the compression ratio. The main problem is detonation, and 100 AKI leaded fuel is not in the cards. DI engines compress air only and inject fuel for optimum mixture distribution, rich at spark plug and very lean elsewhere. Honda’s old CVCC system was a carb-based stratified charge that was ok in its day, but miles from what DI can do.

  • avatar
    Educator(of teachers)Dan

    I postulate with GM putting a DI 3.6VVT in the 2012 and beyond Impala we will soon have a ton of data on DI engines. Hopefully they don’t have the same issue the Northstar does with carbon buildup when not driven aggressively. (Not that that will be a problem for me, but your 85 year old grandfather… not so much.)

  • avatar
    Dirk Stigler

    Point of historical reference: GDI is only new to cars. All German and some Japanese military aircraft engines used it in WW2, and US commercial aircraft engines used it until the end of the piston era.

    These were applications where power output and/or efficiency trumped upfront cost. The combination of increasing weight (due primarily to government-mandated safety devices) and increasing (government-mandated) fuel economy standards have now consumer vehicles to the same point.

    Unfortunately the consumer gets screwed, since even a large improvement in gas mileage doesn’t come close to paying for the extra cost of technologies like GDI or hybrid powertrains, unless you’re a traveling salesman, cab driver etc.

  • avatar
    TR4

    Not new for cars either. The Mercedes 300SL used it in the middle 1950s. They soon figured out that port injection was a whole lot simpler and almost as good. Nowadays though emission control and fuel economy make GDI worth a second look.

    • 0 avatar

      Don’t forget computers. Computers (EFI) makes DI a far smarter proposition, especially after experiencing a 300SL for myself.

      https://www.thetruthaboutcars.com/2010/07/review-1958-mercedes-300sl-factory-restored/

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