So I get 150 to 200 miles per tank and when I went to go calculate my mpg it said I only got 8 how I got it was how many miles I went divided by how much the tank holds

 

You've got something majorly wrong. Any check engine lights?

 

That's not how you calculate your mileage.

Start with a full tank, drive until you refill. Then take the mileage and divide by what you put into the tank, not how much it holds.

 

ignoring his erroneous math, 150-200 per tank is pitiful.. I get the better part of 275-300 even with my heavy foot, averaging 12-14 calculated correctly.

 

Still if he is only getting 150-200 a tank. I was getting at least 250-300 on a tank

 

Yea my 3.9 gets around 250-300 15mpg basically

 

Nor does basing your mileage off of "distance per tank" mean anything unless you're literally running it out of gas.

Gas gauges do not give you a good idea of how much is left in the tank, furthermore, when the fuel light comes on in a Dodge, there's typically ~5 gallons left.

 

i dont have any thing wrong no lights no nothing it dosent make any sense but i can go like 2 weeks per tank and i fill it up with about 18 gal everytime

 

i also use the trip meeter and i clear it everytime i fill up

 

Full your tank all the way . Let's say you drive 100 miles, then fill up all the way and it takes 10 gallons. You then got 10mpg