Contour Enthusiasts Group Archives Forums General Troubleshooting 99 SVT only getting 19 Mpg consistantly

had 19-20 mpg for the longest. changed O2s, jumped to 24-25. lately it's been a bit lower, dunno why though

i get 22 .. but i drive my car hard.. I can live with it.. I want to do a UIM/LIM cleaning see if it helps

You are nitpicking about little things. Those type of things can indeed cause your calculations to be off by 1, maybe 2 mpg. But this is not the problem - 19 mpg is far, far too low for a CSVT.

I do agree with the UIM/LIM cleaning. Do it and see how much that helps - after, of course, checking the fuel filter.

I don't quite understand how a clogged fuel filter affects mileage, could anyone explain it to me?

Thanks!

well my car has 33,000 miles and the filter was still the original one. so i changed it this morning. i'll post weather this helped or not as soon as i can tell.

As Ray said earlier in this thread, it's because a clogged fuel filter will affect your air:fuel ratio, and anything that does that will negatively affect both engine performance and gas mileage. A clogged filter usually won't affect your gas mileage quite that much though, so my first guess would be a bad oxygen sensor, since that's pretty much the worst thing that can happen to your gas mileage. But in that case, there'd be a CEL to indicate the bad sensor, and since that's not the case... then who knows.

Changed the fuel filter about a week ago and went through the first tank of fuel. Considering that the tank was run 1/4 down with the old fuel filter (19 MPG) and the small (?) amount that was lost when changing it, I got 23 MPG on this last tank! Im only guessing that the next tank will be higher . I would've never thought that a fuel filter could make that much of a difference... Thanks for the suggestions, everyone!