Tacotex

I recently made a trip to CO for a MTB race, from Houston, TX. Drove north to Kansas, then west to Denver and up into the western slope. Traveled south through Aspen and Independance Pass. The point is, after a brief adjustment period, the cpu adjusted the air/fuel mix. I burned a tank of gas at constant alt. of 9-12K ft. I filled up with just over 370 miles on the last fillup, and took on 16 gallons on an 18 gallon tank. In any case, the calculator came up with over 23 mpg. I'm guessing that the computer leaned the air/fuel mixter to adjust for the altitude, and that others have had similar results with sustained high altitude driving. My current average mpg is about 18.5 city/highway-exactly where it was before I left 100' above sea level. My question is: what sensors (02?) are key to peak air/fuel adjustments?

rimpainter.com

Bank 1 (front 02) and MAFS.

The same thing happens to me at high altitudes. I got 21 mpg as my best though (before I was SC'd) - not sure what it would be now.

Tacotex

Thanks for the info

rearviewmirror

OFF TOPIC.. Do you race the TMBRA series?

Mr.mud

How much of your improved MPG do you think is from the computer leaning out the mixture VS the thin air having less drag on your truck? Just a idea not sure if it even makes a differance.

kevin444

highway mileage too!

Tacotex

Not very often. My last two were the downhill races @ Kerrville and Comfort. I was at the Snowmass national last month, racing sport DH 40-49. I ride a silver Bullit, and my name is Pete. How about you?

Tacotex

I'm sure that has some affect, but keep in mind that speeds are slower up in the mountains than on wide open interstates, so drag is less as well (I think).

rearviewmirror

I raced the Sport 20-29 class (XC) I went to expert in the spring, this fall will be my first full series in expert. I rode the DH course @ Comfort last year, it was good fun, of course I did it on a Racer X, so it was hard to carry any real speed.

Roadtripr

I got 24mpg only once, and that was driving at higher altitudes. It always seem I get better milage in the mountains. But I think the facts are biased due to more relaxed driving when in the mountains (vacation) than a normal work day high speed traffic