User24

iTrader: (1)

While driving California to Illinois, there came a point on Interstate 80E, somewhere in Ohio, where I could no longer accelerate. 5th gear, 4th gear, 3rd gear, gave me nothing. At this point I've dropped to 45 mph already, so I try 2nd gear... nothing. I figured my poor engine was just tired and heatsoaked through so many miles in such a short period of time. I figured its all clogged up with carbon. And I actually saw monster trucks out-accelerating me. One of my last thoughts was going rx8clubbing and joining the new engine club.

After some rest, and with my logical thinking returning, I looked this up on the internet. I learned the 80 contains the highest elevation point in the entire interstate system. While I didn't hit the highest point, I was definitely up there a ways.

Interestingly, the class of vehicles least affected by the elevation was trucks of the large variety. Had I been thinking right, I'd have known they'd not be normally passing me up, but I was tired. On the descent consisting of 50 miles continuous downhill, the exact opposite occured. My car just kept getting faster and faster compared to everyone else, until it was ridiculous. Easier revving compared to normal, and extra-normal performance. At least that's how it sounds when your ears are pressurized.

I wonder why the rx8 was so heavily taxed by elevation compared to trucks. Why?

I made some Utah photos, but "kwescott" had beat me to it so I contributed to his thread instead: https://www.rx8club.com/rx-8-multimedia-photo-gallery-6/black-8-w-volks-utah-photoshoot-kolob-canyon-87535/page2/

So now I'm in Illinois... such a terrible place for driving and I'll tell you why if you want to know.

DOMINION

Dam dude that sux. How long have you had your 8? did you ever have the compression test on you'r car?

BigRed

Its unbelievable how much elevation effects any car, especially ours!

DOMINION

Odd I have a AT o4 and have been up here many times
http://www.mtcharlestonlodge.com/

swoope

iTrader: (5)

motor got worked on the way up under load... not really any more oil added... apex seals dry....

after the motor cools the problem goes away.. or you need a new cat.. problem does not go away after cooling...

premix will cover the problem, but you motor likely needs to be replaced..

beers

mikeferz42

took my 8 to lake tahoe (4580 ft) a couple of weeks after i got it and it never had any problems with acceleration. tahoe is 3 hours away from me so the engine was pretty hot during the climb.

MazdaManiac

iTrader: (3)

Altitude will kill power, but it shouldn't kill ALL power.

I just drove in and out of Arizona and Utah via the Grand Canyon and Marble Canyon through the Kaibab forest, often near triple-digit speeds. I moved from 1000 to 4000 to 7800 and back to 5500 and then up to 7500 feet again. The MAP read a 12 or 13 kPa difference at altitude. That is a LOT of air missing.
Needless to say, there were stretches where I was in boost continuously for several minutes.

Tom93R1

I would hope elevation in Ohio wouldnt be enough to kill power. If you took 80 all the way from CA there are plenty of spots in NV, UT, and WY that should have been much worse. Get a compression test

swoope

iTrader: (5)

a compression test will not catch what is going on in this case....

when the motor cools the problem will go away...

hey, but what do i know.. o wait,, i knew how to make the problem happen when i needed to..


beers

Machiavelli

I'm suprised no one else commented on the Ohio thing. That had to be a mistype. First of all, the northern part of Ohio where I80 runs is flat as a pancake. Secondly if you are driving to Illinois from California and find yourself in Ohio, you need to hunt down the guy who sold you your map. You've gone just a bit too far east. As in the entire state of Indiana.

SoundDsnr23

Damn, you beat me to it! Yeah, maybe he was just delirious from having overshot his target by several hundred miles and only THOUGHT the 8 felt slow. Those damn Ohio mountains!!

New Yorker

I'm pretty sure your diagnosis—that the engine just doesn't deal with elevation well—is wrong. Any 8 should be able to traverse I-80—mountains and all—without the acceleration problem you describe! Something's very wrong with your engine.

SureShot

FWIW: Most big trucks are FI..

reaper1

Call your Mazda dealer and make an appointment.
There has to be something wrong with your engine.
Any elevation should not be an issue.

User24

iTrader: (1)

I was wrong. It was interstate 70E.

I followed the Garmin C340 gps, don't remember a lot of the middle states, didn't have to rely on my own memory. Retracing my steps, I went California, Nevada, Utah, Colorado, Nebraska, Iowa, Illinois.

It was in Colorado that I had the most problems among the mountains there. Even stopping for gas at a Conoco the acceleration was slower than usual. As soon as I got down from that elevation, 50 miles downhill, my engine was running smoother/better than normal.

http://en.wikipedia.org/wiki/Interstate_70

"The construction of I-70 in Colorado and Utah is considered an engineering marvel where the route passes through the Eisenhower Tunnel, Glenwood Canyon, and the San Rafael Swell. The Eisenhower Tunnel is the highest point along the Interstate highway system with an elevation of 11,158 feet (3,401 m)."

So, at 11,000 feet, don't you think it reasonable that my acceleration was lacking? I could maintain speed, just could not accelerate any more in that moment.

Also, Utah was all curves, and at very high speeds. Hard to believe, but 1100 miles in the first 24 hours, I never wanted to see another curve again.

MazdaManiac

iTrader: (3)

At 11k feet, the air is about 75% of the density that it is at sea-level.
There is an absolute correlation of power to altitude.

Now, whether it would be a really significant power loss is another thing, but I know that at 7800 feet, I was in boost at load levels that would have been in vacuum at 1000 feet. An N/A car doesn't have that option.

05rx8mazda

iTrader: (4)

This past summer i drove to Texas and back RACING ALL THE WAY BABY!!!! i havent had any issues with my baby..

Seems like she keeps getting faster as she ages lol Idk hah

35K miles and goin stronger than ever lol oh BTW this is like the 4th time i drive to chicago and back lol Fist trip I got like 19 MPG lol Crappy this last time Idk why but i was gettin 23.3 MPG lol 275 miles and still had a quarter of a gas tank left i was impressed..

Kiken_808

You're not the only one with this problem. Before I bought my 8, I rode in my friends one and as we were going up my hill the 8 was really struggling. But coming down the hill was something else. I've never experienced a feeling like that before in my life.

RX26b

Without consulting my atlas, and having made the Chicago to Denver via car through Iowa and Nebraska I can tell you that I70 definitely does not pass through those states.

Are you sure you actually drove to the midwest and didn't dream the whole thing?

User24

iTrader: (1)

70E does not go all the way, but it does connect Utah and Colorado, and that is where I had the problem to the best of my knowledge. You can be positive I did not dream the whole thing, because I have the photos to prove it and have posted them on rx8club already. If you wish I'll scan the gas receipts too. Funny thing too, it was exactly like a dream, the kind where you are running away from something but can't move faster than slow motion, yet you know you can go faster in real life.

Never had a problem accelerating uphill until Colorado. It was that particular stretch through Colorado where my car was sluggish with acceleration. If you have driven there with the rx8 I'd like to know, otherwise we don't really have a common experience base to share.

I had no problems through Utah, long stretch with no gas stations until Green River, went into Colorado, huge curves in Colorado, tunnels through mountains, and the only cars around me were 3 trucks chasing me around. The worst was shortly before descent when I had lost acceleration ability, but soon regained on the downhill. Thinking back, other passenger sedans weren't exactly out-accelerating me at the time, and they didn't gain the extra speed on the downhill that I did either.

Another factor, I was lugging 150-200 pounds of stuff as this was a relocation drive. I think my gas was good, because I only used Conoco in Colorado and that is a Top Tier gas station.

I will try to do a compression test next year when I have time. I'm just hoping I'll never have this problem again if I stay away from Colorado.

I may not remember all the details, because when you find yourself in San Diego on Thursday evening and need to be in Great Lakes, IL by Sunday, you change your oil, rotate your tires, throw the GPS on the dash pedestal, and start the engine.

Lastly, although I have some wacky opinions, due to the documented effort that I put forth attempting to make quality contributions to the forum, I'm not sure how you could justify thinking I am a troll.

MrCairo

You may also want to check that the Oxygen sensor is working properly. A bad oxygen sensor will result in a poor mix of air to fuel especially at higher altitudes.

Senna

I lived in Ohio for a while over a decade ago and from what I recall altitude shouldn't be a problem at all there.

Tom93R1

Colorado altitude is another story. 11,000 feet around Eisenhower tunnel can be rough. Even on a motorcycle you can certainly feel it struggling as compared to much lower elevations. Must say I never had problems keeping ahead of trucks up there though, in anything I have owned. In the high mountains RPM's are your friend. It is better to rev high than to lug it, as too low of RPM is the main cause of the cars you see pulled off to the side of the road overheated. It is likely the car is fine and you just dont have alot of high altitude driving experience. Take this as a new lesson in how extreme altitude can affect your performance.

Flashwing

I've experienced this issue on a smaller scale while attending a Mingus Mountain drive with the AZMC. By the time we got to Flagstaff at Snowbowl the car was not seriously underpowered but I misjudged a pass around a truck due to not remembering the air was thinner and thus wasn't able to quite make the pass as easily.

Until someone reminded me of the elevation change, I was worried I had compression issues.

MazdaManiac

iTrader: (3)

Turbo FTW.
A turbo makes the altitude sea level, regardless of physical altitude (up to a point, but few of us will ever drive around at 20,000 feet).
This is also another argument against SC, since it will produce less and less boost as the altitude goes up.