TPW

I finally took my 5Kqt on a long road trip and found my speedometer (and odometer) was about 7% fast. Besides larger tires how can this be corrected? Also what kind of milage do you people actualy get when driving straight highway miles? I averaged 23 mpg Minnesota to Texas and back.

skiddmark

I usally get around 27-28 when driving about 80mph between home and school.

crotext

Mine is weird but gets 29-31 on flatter highways and lower elevations at 80-85 mph average. I put in a tank of the best gas available last week and the mileage dropped to 24. Go figure! It's beyond me why this car runs better on the mid grade but it does.

computrtutr

I found the same thing in different cars... not all Audi, and not all imports! My theory is this: when you pay more, the engine burns cleaner, with more power, with an inversely proportional relationship to gas mileage (i.e. as power increases, gas mileage decreases in this case) because the fuel is purer, so it burns quicker.

skiddmark

The higher the octane the slower the gas is supposed to burn. Thats why you need higher octanes when running high boost or advanced timing to prevent preignition.