RAV4 Mileage

toyota
rav4
fuel-economy

#1

I drive my 2006 RAV4 to mountains in the summer and spend a couple months at 9000 feet. I carefully check mileage for each tank and always find the mileage about 2-3 mpg better at the high altitude. The rest of year I am at 500 feet. Can anyone explain?


#2

Where the heck are you driving that is over 9,000 feet? My guess is that it’s windy mountain roads that force you to drive slower than you do in the lowlands.

It could also be that you tend to drive slower at higher altitudes because your engine produces less power.


#3

I agree, it may have more to do with driving habits, load stc than the vehicle. It could also be a result of that inflated hot air balloon you have in tow.


#4

One factor is that there’s less air resistance at higher altitudes. I don’t know the exact density change, but for 8500 feet it’s probably significant.


#5

At the speed you are driving at that altitude, air resistance is a very minor factor. The low speed in the mountains is the likely cause of the mileage increase.

One long weekedn I came back from a mountain resort, and the traffic was heavy, so I could never exceed 40 mph. The mileage over that trip was great, but had nothing to do with the altitude!


#6

in the 80’s i had a mazda GLC with a carburetor, and when i would drive from boulder colorado at 5000 feet to ohio at 800 feet my mileage would steadily go from 35 mpg down to 25 mpg. i attributed it to thinner air (less resistance) at higher elevation and less molecules of air sucking gas through the venturi in the carb. definitely had more power at lower elevation but i’d rather have the better mpg. when i would go up into the mountains, up to vail, etc. at 10,000 plus feet i would occasionally get up to 45 mpg, even after cranking up long passes in 3rd gear it would average out much better mpg the higher i went. this car had an automatic altitude adjustment but it’s method of function isn’t something i recall. i would vote for the air resistance and less gas being injected to maintain proper stoichiometry as the two main factors. if low speed was so significant it wouldn’t explain my situation as i was driving at the speed limit as much as i could- this was on interstates 70 (vail) and 80 (trips to ohio).