So flame away. I am FAR FROM a math wizard, so your help is much appreciated. I have searched the forums well and have not found anyone with the same overall tire diameter as mine.

I followed Ian's instructions on the INFO page to determine my overall tire diameter is 30.2 inches (31x10.50 15's) compared to the stock tires at 29.61. My speedometer is reads about 1.5 mph slower that I am actually going. That will make it appear to have less miles on the ODO than there actually is.

Would the easiest way to determine my MPG be to drive along the interstate and follow one of the "speedometer" check sections?

Thanks for the help. And please, do not flame too much!!!

Right On! Thanks MUCH! I will do that today when I get gas!

Thanks again...

Lonnie,
It would be more accurate if you could drive the highway and make note of the highway milage markers on the side of the highway and then compare it to your odometer. The farther you could drive the more accurate the results would be.

Math:
Drive 100 miles according to the mile markers
Odometer reads, lets say 97.6
100 miles/97.6 = 1.02459016393 or 102.5%
So now lets say that you fill up at the gas station at some point in time. You put in 15.693 gallons of gas and your odometer reads 260.3 miles. So you take 260.3 * 1.025 = 266.8 actual miles, then 266.8 / 15.693 = 17.00 miles per gallon. I hope this helps.

That helps. I will figure it out! Thanks MUCH for the input.