ANy ideas what can cause a 2.3 mustang to get the same gas mileage as a 5.0? I already changed the plugs, wires, and distributor cap, so I know that's not the problem. It helped a little, but I'm still not getting any better than 20 mpg.

driving habbits... don't accelerate hard (yeah, like you can STOp doing that :D) tire PSI, air filter, .... maybe fuel injector cleaner?

Originally posted by Kraw
driving habbits... don't accelerate hard (yeah, like you can STOp doing that :D) tire PSI, air filter, .... maybe fuel injector cleaner?

Check, check, just replaced, fine...

oxygen sensor?

Try doing a code scan. The Ford scanners are about $30 and attach into a plug near the driver's side strut tower. That will tell you if any sensors are bad.

The thing is that engine is not really an efficient one and like Kraw said, you probably have to floor it alot just to get in traffic. If you have a friend with some Mustang performance parts like ignition upgrades you can experiment. I would think a Jacobs ignition would help quite a bit because you can widen the spark plug gaps and get a fuller burn in the combustion chambers.

Originally posted by jillianjiggs


Check, check, just replaced, fine...

oxygen sensor?

Yes, maybe the OX Sensor, but driving conditions are more likely it. Drive it to LA on I5 and you'll be surprised what kind of mileage you'll get. Put'in around sacto and Rose***** will burn more gas, during commute hours especially.

I don't drive in town...I'm on the highway most of the time...Farm roads :)

And it's not really THAT bad that I have to floor it to get into traffic, just when I'm trying to merge on the freeway at night when everyone is driving like hell.

Hard accelleration from a stop will kill your MPG more than you think.:( I think I heard something on the radio news a few weeks back to the tune of 15-20%.

Anyway, barring tire pressure or a bad O2 sensor, I'd have to say it probably is carbon build-up. Most of the store bought 'injector cleaners' don't work worth a darned IMO. Hell, the cheaper ones are actually just octane booster, which promotes carbon build-up in a normal compression engine.

Assuming you're not willing to spend the money to get a professional intake system cleaning (& I don't blame you too much there based on what the shop I've worked at charge.:( ), I'd try one of the more expensive injector cleaners for a few tank fulls of gas & see if that helps. Personally, I like Red-Line's cleaner there. It's available at most Pep Boys too.:)

tire pressure and air filter are big ones. 20 MPG is prolly about what you can expect for that car. My 5.0 is lucky to get 13-16 MPG IF I keep my foot OFF the blower :D