By on November 15, 2016

2017 Fiat 124 Spider

Kirk writes:

Sajeev,

I asked Bark for advice a few months ago and this question is somewhat related: I’m now planning to get a Miata or maybe the Fiat 124. I live at 5,000 feet above sea level and from what I’ve read, it sounds like the average naturally aspirated engine loses 3 percent of its power for every 1,000 ft increase in elevation, which translates to a 15 percent power loss at 5,000 ft. However, it appears that turbo engines do not suffer as much, as they lose about 1.5 percent power per 1,000 ft on average due to the less dense air. (i.e. more dense with forced induction – SM)

If that is the case, than I expect it would be better for me to get a turbo engine — provided I’m okay with the Fiat.

We may also get an Accord in the next few years, so I wonder if it would be better to buy a six-cylinder NA 2017 next year or wait for the 2018 Accord turbo.

I’m just trying to understand the pros and cons of NA vs turbo engines at elevation.

Thanks for you help!

Sajeev answers:

The benefit of turbocharging is clear, to the point that the Lincoln MKS became almost interesting in this uber-sandbagged comparison test pimpatorial. Which means absolutely nothing to this Houstonian, but do you really care? 

You do not, and here’s why: back in 2013, I rented a new, 148-horsepower Hyundai Elantra in Bernalillo, NM (5,000-plus ft elevation) and never needed more power. It was remarkably okay, even in the steep hills and twisty backroads north of Santa Fe. I never regretted rejecting the turbo Sonata sales pitch from the guy at the rental counter for just this reason. (Though I admire his brilliant forced induction sales pitch!)

Read between the lines and you’ll note my sinister plan to get you to really quantify the benefit of forced induction in your commute, and your driving preferences.

You pay extra for the privilege, plus there are more parts to wear out, and sometimes more labor to work around it (and its plumbing).  So, quantify the benefit: I doubt it matters one iota on your future Accord purchase. After my time with the Elantra in New Mexico, you’re probably fine (i.e. content but not thrilled) with a naturally aspirated four-cylinder Accord!

But I do see the need desire for the extra torque and power (and the elevation benefit) of a Fiat 124 over a Miata.  Can’t blame you for that.

[Image: Fiat Chrysler Automobiles]

Send your queries to [email protected]com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice. 

Get the latest TTAC e-Newsletter!

Recommended

52 Comments on “Piston Slap: High-Altitude Aspirations?...”


  • avatar
    dividebytube

    The last time I flew out to Colorado – was that really 15 years ago?? – I rented a then brand new Corolla. It did okay in Denver, but really started to struggle going up the roads in the Rocky Mountain National Park.

    Before that, I used to live in Boulder and got around fine in a 1984 Nissan Sentra wagon with an automatic! Of course that wasn’t exactly a canyon carver.

    • 0 avatar
      Nick 2012

      Rocky Mountain NP kills anything without forced induction. I took my family through there in an overloaded Hyundai Sante Fe Sport with the 2.4 n/a motor.

      Never in the history of internal combustion has so much noise produced so little forward motion.

      • 0 avatar

        No, the Ford bore-us I rented in Bozeman, MT as it went over the continental divide. Mayhem but not much motion.

        Next Trip, had my SAAB 9-3 turbo. It made great (well, normal) power up the divide, motoring past n.a. cars like a boss. You could tell the engine was still working harder, and the boost curve felt different.

  • avatar
    energetik9

    I remember taking a NA Mustang rental up Pike’s Peak (a little too fast probably). Never noticed an issue. Granted the experience may be different with a low HP economy car.

    Buy a forced induction car for performance and maybe MPG (if you can keep off the throttle). Don’t buy it for modest HP gains at elevation.

    On a side note, I hear great things about the Fiat.

  • avatar
    scdjng

    Kirk, just a side note about the 1.4 turbo. It’s an okay motor. It sounds good but it isn’t as high reving or free spirit as Fiat would like you to believe. I have one in a Dart and have not had any problems after 65,000 miles. It does hate cold weather. Below 45 degrees it needs to be warmed up before driving.

    • 0 avatar
      Malforus

      On that topic,

      I have not been hearing lots of performance/rewarding driving characteristics about the 124 vs. the Miata. It might be a better idea to wait for the midcycle refresh on the Fiat as there is some suspension tuning left on the table and the fit/finish isn’t as high quality.

      Hell C&D found the Miata was faster around a road course and will of course have fewer maintenance issues thanks to a more proven and tested platform.

      • 0 avatar
        Vulpine

        Nearly everyone has said from day one that the Miata is the “better” car. But they have also said the Fiat tends to be more fun BECAUSE it’s not as forgiving. As for reliability, the two should be almost identical; the platform is the same and Fiat’s engines and transmissions are NOT the subject of any negative reliability ratings over the last several years.

  • avatar
    FreedMike

    I’ve found that here in Denver, there isn’t much of a difference between turbos and naturally aspirated engines while you’re in town. The turbo’s payoff comes when it’s time to get up I-70 to the mountains – you’ll have something of a power reserve at higher altitudes, where a small, naturally aspirated engine won’t.

    Do you really need a turbo, though? Meh. I made it up I-70 just fine this summer in my girlfriend’s Hyundai Accent – you just floor it until you’re at altitude, and then you’re fine.

  • avatar
    PrincipalDan

    So what is THE TRUTH ABOUT modern engines and altitude? Obviously this is not the 1950s when my ex-wife’s grandfather would drive down Route 66 to Gallup NM and stop in Santa Rosa, NM at a shop he trusted and have them set up the carburetor for high altitude operation.

    How well does the modern naturally aspirated gas engine compensate?

    • 0 avatar
      heavy handle

      The truth is that modern engines automatically compensate for lower air pressure, so they don’t run as rich when going over a high pass in the Rockies. That means more power and less fuel use.

      Modern cars also have more power reserve compared to the 1950s. I’ll bet you could really feel the loss of 40HP in a 100HP, 2 ton car when going uphill. Losing 40 hp in a 260 hp car means that you are using slightly more throttle (but still not full throttle).

    • 0 avatar
      Flipper35

      ALL modern engines compensate just fine. That is what the mass air, O2 and other sensors are for.

      • 0 avatar

        And multiple air/spark tables.

      • 0 avatar
        NeilM

        Flipper35 writes: “ALL modern engines compensate just fine. That is what the mass air, O2 and other sensors are for.”

        That’s true as far as drivability goes, but those compensations do not and can not restore the power lost to reduced air density at altitude.

        That said, I’m inclined to agree that all but the most minimal of cars have a decent enough power to weight ratio these days that they can suffer the power loss at altitude without it becoming a big deal.

    • 0 avatar
      Pete Zaitcev

      Modern engine’s computer receives the information from MAP sensor and selects a tune based of it. It’s like a N-dimensional matrix with pedal position, RPMs, MAP, OAT as inputs, and injector timings and throttle position as outputs. It is algorithmically compressed and has corrections applied for changes in pedal and possibly VSC. Results are effected through injectors and the circular linear motor at the throttle body (unless it’s BMW with Valvetronic).

  • avatar
    dougjp

    The OP appreciates and values power/torque. A number of people responding including Sajeev clearly don’t care much. Hence, mismatch and ignoring the reason why the OP wrote in the first place :(

  • avatar

    That little 124 strikes me as the only true jewel in Fiat’s lineup.

  • avatar
    mittencuh

    Personally I feel a huge difference between here in COS and when I’m back in WA, doesn’t matter if the car is NA or not. This altitude really exaggerates turbo lag. Can’t stand it.

  • avatar
    TDIGuy

    I suppose if you can hold off until both models are available, getting out and test-driving would be your best choice.

    It is really depends on the torque band. On the interstates in Virginia and West Virginia, I found the wife’s 3.5L V6 Santa Fe has to drop a gear to keep the 70MPH speed limit while getting up some of the mountain. Yet at 80 (which is what the locals drive at anyway), despite increased wind resistance and whatever, it usually stays in the same gear.

    On the other hand my Golf TDI chugs right through it all with no problems.

  • avatar
    slance66

    I like the Fiat 124 better than the Miata/MX-5 anyway. If living at high altitude it seems like a complete no brainer.

    On the Accord…wait only if you really prefer the next model to this one. Or get something else. There are 2.0T sedans all over the place.

  • avatar
    CoreyDL

    Which car rental companies try and upsell you to a bigger car? I’ve never had them do that to me at the green E.

  • avatar
    JMII

    One advantage to turbos come in the form of available upgrades or modifications for them. For example your normally just ECU flash away from another 20-50 HP.

  • avatar
    Vulpine

    Having lived in Denver myself before turbocharging became so popular, I have to ask one question: How often do you travel up into the mountains? Have you ever gone up Pike’s Peak?

    Why do I ask? Because at 5000 feet the difference is hardly noticeable from sea-level performance BUT, even with a 200hp V8 at the time (1984), the climb to Pike’s Peak had me take over a half-mile to pass a 75-hp VW Beetle at about the 8,000-foot level (one of the few long straights before hitting the mountainside itself.) So it really depends on where and how you intend to drive your roadster. Considering the type, I’d expect you to head for the twisty roads which will take you higher than the city and demand more power as you climb higher. If so, then I strongly recommend the turbo. As for which car to choose, that’s on you. If I could afford a toy I would certainly buy the Fiat over the Mazda. but if you need some semblance of practicality, the Honda may be the better choice.

    • 0 avatar
      kclindley

      If I get a roadster I’d head up the canyons/mountains frequently which would take me up to 9,000 feet. I’ve driven both cars at 5,000 feet and prefer the linear feel of the Miata as it takes a bit for the 124 to get going due to a little turbo lag. Recently I drove a BMW 228i coupe (now 230i for 2017) as I’ve read great reviews about it. It’s a blast to drive and now it’s on my list. As my old car keeps running I can continue to save and have more options.

      Maybe I should just get V6 Accord like Jack Baruth. Here’s his take on it: “I’ll sum it up like so: The Accord EX-L V6 coupe does 95 percent of what a $60,000 German coupe does, at half the price, while probably lasting twice as long. It’s not a perfect car, but it’s good enough for the way I live now.”

      https://www.thetruthaboutcars.com/2016/01/accord-thirty-thousand-miles/

    • 0 avatar
      FreedMike

      +1 to Vulpine.

      It depends on where you intend to drive in the mountains, and how you intend to drive once you’re there. If you’re just slogging up I-70 with everyone else, you don’t really need a turbo – you’ll get where you’re going with a little (or most likely, a LOT) of WOT. But it’s going to be a slog.

      Now, if you’re going to buy a two-seat sports car with the intention of hooning it around on winding mountain roads, at altitude, then slogging may not be what you want.

      Best suggestion – try both the Miata and the 124 at a higher altitude and see how they perform. My guess is that there won’t be much of a difference, but to a car freak (i.e., the kind of person who would buy said Miata in the first place) it might be significant.

  • avatar
    kyngfish

    You can also tune the SHIT out of the multi-air. So do it.

  • avatar
    87 Morgan

    The after market exists to solve your problems here in the mile high city.

    Open up the intake, full K and N or one of the other options, make it easier for the air to get in. Next, open up the exhaust. Again, many options available to keep the noise down and flow up. I am a flowmaster guy, every kit i have purchased bolted up like it should and made a huge difference.

    These two mods on my Wrangler made it actually usable and in fact it will get out of its own way.

  • avatar
    ttacgreg

    Here is my two cents worth.
    At altitude there are two ways to get air into the motor. One without a turbo you downshift and use more RPMs. The other is with the turbo you leave the car in higher gear and the turbo does the job for you.
    Less noise,less gear shifting and I suppose theoretically less internal frictional loss for better miles per gallon and engine where.

    • 0 avatar
      ttacgreg

      Too late to edit so I will reply to my own entry
      I should have mentioned that above 10,000 feet my turbo vehicle requires higher rpm’s to get the positive feedback feedback loop of more exhaust makes more boost, makes more exhaust going, additionally boost takes longer to build because the turbo has to spin at far higher rpm’s at high altitude to push enough air into the intake to produce positive pressure.

  • avatar
    LeeK

    I’m typing this at 7000 ft of elevation here in Santa Fe. Two years ago I moved from the east coast of the US near sea level and am still driving the same turbocharged Mark VI GTI. If there’s a difference in my car’s performance nearly a mile and half higher, I sure can’t tell via my butt dynometer. The only time I can maybe detect a miniscule difference is in the summer when the air is hot and thin and coming off the line from a dead stop the car is a bit sluggish for about a second until the turbo spools up. This disappears in the fall, winter, and spring months with cooler temperatures and denser air.

    My wife’s normally aspirated 280HP SUV should be affected by the elevation change, but darned if I can tell the difference, either. Of course, it was never a speed demon to begin with so I chalk it up to the miracles of a modern fuel management system. Yes, there are numerous 0-60 comparisons that have been done for identical cars (Roman Mika’s video reviews often mention this) and performance does drop off about a second or so. But in real world conditions, I can state from experience that it’s no big thang.

    TL;DR: Get the Miata and you’ll be just fine in the Rockies.

  • avatar
    probert

    Considering recent events, whatever you choose should have lead shielding – it will give you few moments to make peace with your maker. Apart from that, the Miata is far better looking.

  • avatar
    Wagoon2.7TT

    Anecdotal account here, but I live at 6,000 feet and have a naturally aspirated and a turbo vehicle. A 350Z and a turboed German luxobarge, for reference. There is a super fun twisty mountain pass near me that peaks at about 8,000 feet. Toodling around town I really can’t perceive any power difference, but when driving aggressively up the pass, I can definitely feel the NA car gasping for more air. With the turbo car, all I have to do is ask for more boost and the power is there.

    Also anecdotally, I took the 350 on a roadtrip at sea-level and could really tell a difference.

    TLDR, I’m guessing that you would feel a difference when driving at higher elevations nearer the limit, but likely not when just cruising around.

  • avatar
    AdventureSteve

    I live at sea level, but like to travel. I’ve taken my 2014 Wrangler to Colorado, up Pikes Peak, and done plenty of highway and off road travel throughout the Rockies. I honestly never noticed I was down on power, but then again I don’t drive it like it’s a race car.

    Edit: I drive a manual though, and you will too, right :-)

  • avatar
    greytraveler

    We have a 2008 MX-5. Live at 6,500 feet. Often travel at altitude. Since we enjoy the twisty back roads never felt the need for more HP. And, tweaking the engine adds more points of potential failure. The Miata, in my experience, is as reliable as a stone axe. I did plenty of research before buying. My neighbor’s new Porsche 911 is a hoot to drive. But he pays more than 35 bucks for a oil change. And has a bit more maintenance. Take your pick.

  • avatar
    Russycle

    I used to have an NA Mini. Took it skiing once, the lodge was at 5700 feet. I’d say the last thousand or so feet of climbing I could really feel the motor struggling. If I were running a sporty four-pot in the mountains, I’d go turbo.

  • avatar
    Hoon Goon

    Everything is better with forced induction, whether at sea level or 15,000′. Sure you don’t “need” it, but if we all went by that boring outlook we would all be driving around in Tuk Tuks.

    This is the song of my people!

  • avatar
    VaderSS

    Of all the naturally-aspirated vehicles I’ve driven over the passes in California, the 2006 Miata suffered the least and never struggled. I’d expect the current Miata to do at least as well.

  • avatar
    dal20402

    I took my LS460 to high altitude for the first time last summer, reaching a maximum of 8,000 feet in the Rockies. The V8, normally effortless at any non-felony speed, definitely had to work a bit harder, with more downshifts and more time in lower gears. Nearing the top of the passes, it felt like the 367 lb-ft in the midrange had become closer to 300 lb-ft, like I’d expect to experience in a big sedan with a stout V6. I expect a turbo-six 740i would have easily run away in a drag race up there.

  • avatar
    JREwing

    Take the Miata, add an LS motor to it. Problem solved. :D

    https://www.flyinmiata.com/


Back to TopLeave a Reply

You must be logged in to post a comment.

Recent Comments

  • SPPPP: Did the steel beds get a lifetime warranty? I don’t remember that happening.
  • Bigazfordtruck: Agreed, however the local push seems to be for the boulevard option which will push more traffic onto...
  • SPPPP: For context, FCA’s gross revenue in 2018 was 110 billion dollars (billion with a B), but still, nearly a...
  • SunnyvaleCA: >>> And I’m sorry but if you are going to make design a key point <<< More like: if...
  • SPPPP: Are we suuuuuuuure this is a crossover? Because if this is a crossover, then I think that makes the old Suzuki...

New Car Research

Get a Free Dealer Quote

Staff

  • Contributors

  • Timothy Cain, Canada
  • Matthew Guy, Canada
  • Ronnie Schreiber, United States
  • Bozi Tatarevic, United States
  • Chris Tonn, United States
  • Corey Lewis, United States
  • Mark Baruth, United States
  • Moderators

  • Adam Tonge, United States
  • Corey Lewis, United States