Obviously you mean 4000 feet. Actually MPG is slightly more at higher elevations. You lose approximately 3% of your horsepower for every 1000 feet in elevation but you gain MPG due to less barometric pressure.ktulu221 said:I lived in colorado at an elevation of 40,000 feet and I'm extremely hard on my 02 GXE. I used to get 25 city / 31 hwy. You should expect a few mpg higher then this.