help on a 7.3 please

[Colton55]

Hello My name is colton I just bought a 1996 ford f-250 7.3 powerstroke My main question is I bought in back jan it had standard tires on it comeing over the pass back home I got 23 MPG I have scence then put on cooper stt's in the standard size just a beefyer tred My highway MPG is now 16 MPG and my city is dang near 9-10 Are the tires what caused this major drop??? I dont smell fuel in or around the engine I doont feel like i have lost any power and I keep it right around 2 grand on the RPM'S any help sure would be greatfull cant keep throwing the 4.15 dollars a gallon down the drain

Thank you


colton

[CHUCK]

I'm sure the compound of the new tires and also the rolling resistance is different from the old ones. I dont see that it would affect MPG that much though.

[ToMang07]

I'd be willing to bet you didn't fill it up all the way, and thats why you got 23mpg reading.

No way you got 23mpg with that rig, IMHO.

[Colton55]

im sure of it it was full regardless of what i got and am getting for MPG it has dropped down WAY down I was getting about 300 miles to the tank im now lucky to get 200 what are signs of a bad fuel filter or injectors other that MPG??

[Nashotah7]

I get 20 - 22 mpg on the highway with my '97 running 3:56's

[Dietoremain]

sounds like you definitely have an issue... im assuming you've checked the air filter, brakes(not dragging), etc?

[bleininger]

did you go by the odometer or actual miles. bigger tires will show more miles on your odometer than you actually drove.

[4ds4me]

Originally Posted by bleininger

did you go by the odometer or actual miles. bigger tires will show more miles on your odometer than you actually drove.

Bigger tires will actually show less miles than you actually drove.

[Colton55]

I got the same size tires and I did check my air filter and breaks are not dragging