Just curious here, trying to see what kind of mileage I'm getting around town. Anyone know the capacity for the factory tank? Is it the same for 4cyls and 8s?
You can't check your mileage like that...the tank capacity doesn't matter.
What you have to do is fill up and check the amount of gallons you put in the tank and take the miles driven divided by the amount of gallans you put in the tank.