Since moving from sea level to over 6500ft above sea level, my gas mileage has gone from 12 -13mpg to ~15mpg. I have a few ideas as to what caused this great fortune. One, I am in a small town were the speed limit rarely exceeds 25-35mph however, I am frequently on the highway climbing higher and higher which strains the motor. Two, is it possible that the gas is that much better up here? Three, Is it that my ECU is calibrated (or whatever you want to call it) to this altitude? I was under the impression that the ECU would calibrate itself with altitude. What thoughts do you guys have for this recent bout of luck?