Gas millage HWY trip

[HummerJim]

If you really want to confuse yourself, go to
http://www.fueleconomy.gov. Government mileage ratings are done on a treadmill/dyno type machine at a temperature of 69 degrees F, at sea level, and a pressure of 29.92 mb. Temperatures and pressures other than these will affect your ACTUAL mileage. For the highway mileage rating the average speed is 48 mph with a maximum speed of 60 mph and no wind resistance because the vehicle is on a treadmill or dyno type machine. The highway mpg is done with a warm engine and the city is done with a cold start up. Obviously most peole realize these figures are not real world and should be used as a baseline comparison only. The notation at the bottom of the government blurb says it all, "Your mileage will PROBABLY be 5 to 25% lower in actual driving conditons. Government ratings are with a professional driver under laboratory conditions."