I bought a 1994 GT back in May and have been working on it ever since. It's got 104,000 miles on it. I've replaced the plugs,wires, cap and rotor, flushed the coolant system, put a K&N air filter in, and changed the oil and filter using Mobil 1 synthetic. The only performance thing that is on this car is a BBK hi-flo h-pipe. It just has 2 hi-flo cats on it and then the exhaust is routed and exits right in front of the rear tires. The car only gets 160-170 miles to the tank! That's about 11 miles per gallon. From what I've read, the stock city mileage is 17mpg. Some people I've talked to have underdrive pulleys, gears and more performance mods and they still get better gas mileage than I do. Even when I drive I try not to stomp on it. Does anyone have any ideas as to why I could be getting such bad gas mileage? I would appreciate any and all advice. Thanks.

Adam

[spyder]

what gear ratio do you have? is it automatic or manual?

i have a automatic 94 gt with 3.73's and get over 200 miles per tank. it could be many things, but need more imformation about your car.

I have stock gears and my car is an automatic. Nothing else has been done to this car performance wise. Everything is stock on the car.

[Amustang42]

Have you done a compression check on the motor to see what kind of shape it is in? Does it blow any smoke on start-up? Have you cleaned the MAF? Have you tried any fuel injector cleaner? There are many things that you could do to make it better, but you need a baseline to know what kind of shape the motor is in.

[GT Dan]

With that many miles and an automatic and depending on how it was driven by the previous owner, you might have a big problem there.

[Vortex]

well driving is a big part of it... you could have some drag on the car like wheel bearings/hubs, or brakes sticking etc... its difficult to tell on here but we will help you out.. has it been like this since you've owned it?
i would try and pull a code or two.

Yeah, it's been like this since I bought it. I had a mechanic that I know check it over before I bought it. But they didn't do any computer diagnostics or anything. I'm actually going to replace all the brake components tomorrow. So maybe that will do something. I haven't the MAF yet. How exactly should I do that? I haven't done a compression check yet either. It doesn't blow any smoke on start up either. My uncle owns a auto shop and I've had some exhaust work done and my rack and pinion replaced there. He said that he was impressed that it was in such good shape and that it runs so good for having 105K on it. But he doesn't know about the gas mileage problem. Is there any way I could pull some codes myself or should I just have a mechanic take a look at it? I'm not exaclty sure what else to do. Like I said, I still have to do the brakes, and maybe a lower control arm, but, it's nothing too serious. Hopefully I'll get things sorted out here. Thanks a lot guys.

Adam

[Amustang42]

You can look in the tech section on the website to see how to pull your codes!!!