Contour Enthusiasts Group Archives Forums General Troubleshooting BAD MPG!

Just intalled Ford 9mm racing ignition wires and new Motorcraft spark plugs. Seems to run better but the MPG is approximately 16.5MPG. The car is a '98 GL tour with the Zetec engine and ATX. What should it be? I have gotten 23/25MPG in the past. What should it be and what could I do to get better gas mileage? The MAF is clean, O2 sensors are good and there are no CEL codes and it just passed the state inspection. With the mileage this bad wouldn't the HC readings be high?

Bill

I would suggest resetting the computer (Fuse 4 and 11) and then tires to proper inflation, remove all unnecessary items from the car/trunk (luggage rack, tools not necessary for regular driving emergencies) . In addition, let it go a few more tankfulls before wondering if there is a problem with the car.

Hey Bill,

Looks like you've got a doozy of a mileage drop-off there.

I saw the MAF is clean, did you CLEAN it, or does it "look" clean?

the O2 sensors wouldn't be a first suspect to me, either way. (not for THAT kind of mileage drop).

When is the last time you changed/cleaned your air filter? Changed your fuel filter?

Have you noticed a decrease in performance at all? (clogged cats, etc, is what I am trying to get at)

The plugs were gapped correctly and wires installed in the right order?

For such a huge drop in mileage, I would suspect one of two things (if not something, or a combination, from above);
Poor math skills ( ) or a fuel leak, maybe?

I'd look in to the things above and then let me know... we'll go from there, but no one thing above should drop it that much. Keep in mind weather(humidity, temperature, etc) will affect mileage to a degree, as will driving style.. combine those two, with perhaps two of the upper issues and you may see a 5 or 6mpg drop, easily!


This is kind of unorganized, but its coming out as I think of it.. Of all the things I would suspect a clogged exhaust (failed cat, etc), poor fuel pressure, or fuel leak !!!

Ray

Perhaps maybe it is a psychological problem. You got those new plugs and stuff and you want to see if they make you go faster, it's only natural for that to add a couple pounds to your foot subconciously. Once the novelty of the new equipment wears off, you should get better gas mileage.

Looks like you've got a doozy of a mileage drop-off there.

I saw the MAF is clean, did you CLEAN it, or does it "look" clean? Mechanic at the shop that repairs my car did it. .

the O2 sensors wouldn't be a first suspect to me, either way. (not for THAT kind of mileage drop).

When is the last time you changed/cleaned your air filter? Changed your fuel filter? Less than 1,000 mi. Last oil change.

Have you noticed a decrease in performance at all? (clogged cats, etc, is what I am trying to get at) NO

The plugs were gapped correctly and wires installed in the right order? [b Plug gap .052in and wires removed and replaced ONE AT A TIME. .

For such a huge drop in mileage, I would suspect one of two things (if not something, or a combination, from above);
Poor math skills ( ) or a fuel leak, maybe?

I'd look in to the things above and then let me know... we'll go from there, but no one thing above should drop it that much. Keep in mind weather(humidity, temperature, etc) will affect mileage to a degree, as will driving style. combine those two, with perhaps two of the upper issues and you may see a 5 or 6mpg drop, easily!


This is kind of unorganized, but its coming out as I think of it.. Of all the things I would suspect a clogged exhaust (failed cat, etc), poor fuel pressure, or fuel leak !!!

Ray