Terrible Mileage, help please!

[302'Stang]

I've just recently acquired an 88 Foxbody 302 and I averaged 12.8 MPG on the last tank. These cars should get like 16 city and 24 highway, so 20 average? I have been very heavy on that skinny pedal on the right side that make it go fast, but should it really be that bad?

It is burning a pretty rich and has an exhaust leak. I thought maybe a good dyno tune would improve the situation. And maybe a new cat back system. I've also been driving a lot of curvy country roads much more than highways.

 

[302'Stang]

Question still stands.

 

[Ford1288]

What rear gears do you have?

 

[PACOS50]

You've kind of answered your own question! Yes being heavy on the skinny pedal will make it that bad! Remember the "ratings" a vehicle gets are based on "normal driving" whatever that means to the manufacturer. I will tell you though that the exhaust leak depending on where it is, is compounding your problem. Mine had a leak right where the header (I have long tubes on mine) meets the head, and the gas mileage went down the drain as soon as it started. Once I replaced the gaskets it went back to it's normality. No offense though but why are you worried about gas mileage on a Mustang? If you're that worried about gas mileage, a Mustang, especially a Fox, is not the car to have. I don't mean to be rude or suggest that you should be stopping at every gas station and stuff to enjoy your car, I fixed mine not due to mileage but to the fact that I didn't want to mess anything up and I hated the noise!

To alleviate your problem though I would suggest that you fix the leak and get a tune up done on it, cap, rotor, wires, plugs, oil & filter, and the one everybody seems to neglect, the air filter. That should get your Pony running right again! Good luck!

 

[302'Stang]

I have 3.73 gears!

Thanks for the advice, I guess I did answer it, but those were all my theories haha. I did lay off just a little and when I filled up today, I averaged 15.4 MPG. I'm not worried too much about the mileage obviously since I bought the car haha, but 12.8 MPG and 20 MPG is quite the difference at the pump. This is my only car! (once the other one sells) I do plan on getting the exhaust leak fixed, and I just cleaned out the air filter a few days ago. Everything else is all pretty new, too, so it's pretty much had a good tune up!