I have a 99 Escort SE with 148K highway miles. The car has been maintained perfectly. The only problem is I seem to be getting around 24MPG Highway, 20MPG City, on 89oct. It has no trouble starting, idling, or accelerating. Its got an auto trans. Im thinking about putting in a Zetec engine if this one cant be fixed, but id rather not have to do that. Any idea?

well i have a 97 escort with the same engine and auto trans. i average around 30mpg around on the highway and about 28 around town. my gas mileage dropped when the air filter became dirty. also check your oxygen sensors. by the way, that is on 87 octane. it doesnt really add much to use 89. so save some money and get the cheaper stuff if its avaliable in your area.

The air filters clean. How do I check the oxygen sensor? I have always noticed a big difference between using 87 and 89.

Oxygen sensor oughtta be a fun one to check. You have to buy/rent a special tool due to the sensor having a cord coming from it, I bought mine for like 9 bucks, hooks up to your ratchet, has a slit on one side to fit over the cord, unscrew it and you and probably take it somewhere to have it checked. May be a pain to get off, on my 94 Cavalier I had to put all my weight into it to get it off, heh, cut my hand doing it too.

here, check this out: http://www.thepartsbin.com/oxygen-sensor.html

Run the motor just before you remove it and that will make it easyer, the metal will expand a little.

ahh, yes, also if it's kinda rusted...you can try to tighten it a little more then spin it back the other way to take it off, that helped me as well on my old car.

I had a 99 escort split port , was gettin 28 mpg high way , i had a slight vacume leak in a small hose(hard plastic) had it replaced and the mpg went back to 38. Check mass airflow sensor , check inside to see if the wires that cross the air path are gummed up with road scum.

check your tire pressures too , if your tires are unbalance or un even pressure it will affect the mileage. If you want a bit better gas mileage put the tires at near maximum rated pressure ( 2-3 pounds less) so if its rated 40psi put them at 37-38 psi.

If you want a bit better gas mileage put the tires at near maximum rated pressure ( 2-3 pounds less) so if its rated 40psi put them at 37-38 psi.

I would advise against this. Always inflate tires to the Manufacturers Specs on the Vehicle Placard (Usuially found in the door jam). The manufacturer recommends those inflation levels for a reason. Even a few pounds difference in pressure can create serious handling problems, or other issues with the tires.

I agree with the O2 sensor. These are usuially the culprit when fuel economy is low.

just my .02