Philip: Fill gas tank, don't squeeze in any extra gas after nozzle shuts itself off. Reset tripometer or record mileage if you have no tripometer. Drive until it's time to fill up again. For greatest accuracy, fill up at same pump you used the first time. Again fill tank till the nozzle shuts off, and record both the number of gallons the tank took to fill and the number of miles you have driven. Divide the number of miles by the number of gallons, and there you go!
Cheers,
Jay
99 SVT Ag Frost
