What is my MPG? I clearly don't know?

Question

Okay so i have a

2000 Ford E-150 Passenger Van (4.6 Liter V8)

All the sites i go on have a different EPA Estimate.

Answer 1

Girlfriend is on the right track, except that you divide the number of miles driven by the number of gallons of gas used.

Answer 2

How different?  It all depends on other external factors, such as driving style, weight in vehicle, etc.  That's why they are called estimates.  It cannot be an exact science.

Answer 3

from the gov't website on your van,

13/17

http://www.fueleconomy.gov/f*g/sbs.htm

Answer 4

Fill up your gas tank, write down your mileage. Drive until your next fill up - then write down your mileage again - subtract the starting mileage from current mileage - that's how far you've been on that tank of gas. Then divide the number of gallons of gas it took to fill the tank by the number of miles driven. Viola!! that's your actual miles per gallon.