Danr1,

Glad it worked for you.
Just as a friendly note though, I'm not sure that using another vehicle as a base figure is all that accurate. You should go off of mileposts or speedometer check stations on the highway for the best accuracy.

Also, if you are referring to this article, you are using incorrect numbers in your above formula.

This is how your above formula SHOULD read:
32x3.14=100.48/12=8.37 5280/8.37=631x.0135=8.52

Once again, I'm only trying to be accurate, not argumentative.