Vehicle adjustments for altitude?? (Denver, Lamar: garages, rich, cars)

[ryanek9freak]

Originally Posted by John.Bishop14

Ethanol will lean your mixture and raise effective "octane" rating. You can increase your compression ration at this altitude and get away with it too.

I don't think E-85 is available in the springs yet, is it?

[suzco]

Originally Posted by ryanek9freak

I don't think E-85 is available in the springs yet, is it?

According to the Alternative Fuel Station Locator at Alternative Fuel Station Locator - Find there are 5 public stations in Colorado Springs, plus it's available at Peterson AF Base.

Chief Petroleum 719-473-7760 301 South 10th Street Colorado Springs CO 80904 Public - credit card after hours

Western Convenience Store 719-634-4049 2507 E Platte Avenue
Colorado Springs CO 80907 Public

Phillips 66 719-593-8556 5050 Boardwalk Colorado Springs CO 80919 Public

Western Convenience Store 719-268-2703 2775 Briargate Boulevard
Colorado Springs CO 80901 Public

Acorn 719-633-8423 305 S 8th Street Colorado Springs CO 80905
Public - credit card after hours

Peterson Air Force Base Colorado Springs CO 80914 Private

[Bideshi]

Thanks!!!!

[wankel7]

Originally Posted by Mike from back east

....but my attitudes sure adjusted nicely when I came here. I left behind that DC / East Coast type A crap, got jeans & boots, took lessons to ride a horse, chilled out big time, got friendly and all smiley like.....what, me worry?

My cars were fine....1999 Jeep Grand Cherokee 6-cyl and 2004 Toyota Camry 4-cyl. No problems at all. Funny thing, here they sell gas that is 85 octane, as well as 87 octane and a premium that is maybe 91 octane. I use the 87 octane, per the manufacturer's owner's guide, never had a problem. You may detect some slight sluggishness with initial acceleration, due to less oxygen in the atmosphere at 6600 feet, but my mileage hasn't changed a bit.

s/Mike from back east
don't worry - be happy (everybody singgggg)

You have been wasting money for a long time. 85 octane is fine. I highly doubt the engines in those cars are high compression that need the extra octane. Especially at the altitude you operate them at. Save your self a few bucks a month and put 85 in it. You are actually costing your self performance running higher octane than you need. I know it needs 87 but that is at sea level.

The oxygen at 6600 feet is the same amount of oxygen at sea level. It is the pressure that changes.

[Mike from back east]

Originally Posted by wankel7

You have been wasting money for a long time. 85 octane is fine...

True, but shortly after that old post I switched to 85 Octane. Both cars run just as well and I save money.

[sunsprit]

No, Wankel, the oxygen amount at altitude is not "the same amount" as at sea level.

The percentage of oxygen in the atmosphere is the same, but the NET amount of oxygen per unit volume at this altitude is 15% less due to the lower density of the atmosphere.

Your car's motor gets 15% less oxygen to burn, and much less total air density to compress in the cylinder's combution chamber at this altitude. That's why you can use lower octane fuel, because there's much less pressure in the combustion chamber to initiate detonation, or "knock" (from heat of compression of the intake air charge).

If you "restore" the sea level combustion chamber pressures by installing higher compression ratio pistons for a high alititude based car, you'll need to use the higher octane fuel to resist detonation at altitude, but you may also now get sea level motor performance. Of course, the drawback here is if you then return the car to sea level ... it will have much higher combustion chamber pressure than stock and require yet even higher octane fuel than stock. It's all trade-offs ... peformance vs fuel economy vs fuel cost vs durability vs where the car will be used vs the cost of achieving the performance (compression) gain.

[capepuffin]

I have a 2004 Jeep Grand Cherokee. It ran great back east, now it runs horrible. No get up and go. I mean it is bad!!! I came here to see if there was any adjustments that I could do to it. Is there? I have had the car since it was new and always have done the required maintenance. Change my oil every 3K. If I approach any type of hill, forget it, I might as well walk up the hill!

[ryanek9freak]

well no duh! You think the lack of oxygen has anything to do with it?

Try driving up Pikes Peak, and see how it does.

[capepuffin]

Ummm Yeah, I know the oxygen has something to do with it. That is why I asked the question "are there any adjustments that can be made to make it run better????"

[Bob from down south]

The best "adjustment" one can make to run better at altitude is to add a turbocharger, which will force air under pressure into the cylinders, increasing the power available dramatically. My turbodiesel car rocks driving around Woodland Park and Divide (8000-9000 ft)...my injected but not turbocharged SUV...not so much.

An after-market turbocharger is probably $2500+, though.