Bad Gas Mileage [Merged 9-6]

[99GST]

I am still getting some pretty bad gas mileage.

I am only getting about 19.7 mpg with mostly city driving shifting at 4k.
I have already replaced my front O2 sensor and am looking to replace the fuel filter.

I have a 99gst with about 55k miles on it. Should my fuel filter already be bad?

What else should I check or change? I have NKG plugs and Accel wires are on the way.

Thanks,
Nathan

 

[rockice]

i get about 380 km to a tank i dunno hom many miles that is it seems to eat a lot of gas more then my intrepid 6 cyl but then again neither of my o2 sensors are hooked up

 

[2FST4U]

Hard to believe, 505 miles on 14.2 gallons. traveling pa, turnpike. avg speed was between 70 - 80 miles an hour. with your ocasonal 100+,
35.56 MPG!!! around town driving like a stole it.....280 to 14.00 gallons. 20 MPG. Mods are miner CAI, & Pipe.

 

[RuBiCaNT5X]

My buddies boosted GS gets 380 per tank. I am so jealous. I get about 240 on 13 gallons. Grrr!! It's only gonna get worse too.. The only pisser about AWD..

 

[jsigone]

I get about 330-350 on a full tank. Mostly freeway miles. And thats not babying the car.

Mods
20g, 720cc injectors, 2g mas, 255 FP not rewired and etc.

 

[ltvarney]

Originally posted by 420a-gs95

Fuel Capacity: 15.9

For a 1G? Geez, my car must have issues. On both my 1Gs when the needle reads E, it takes 10 gallons to fill them up. I've heard the sensor wears out, I thought that was only 2Gs though.

 

[diamondude]

This sucks...an almost stock automatic '93 TSI awd....14mpg's around town, 17 highway---I am gonna try a SAFC, then it's time for a new car...hmm maybe an EVO?!

 

[HokieDSM]

Been getting 18-19mpg on my 93 TSi AWD running 15psi on a ported 14B. (see my profile for other mods). Been driving mostly "city" lately, but also been taking the opportunity to do lots of "spirited" driving, usually twice or more per week, so that probably has something to do with the mileage..... about 215mi on a tank, filling it to 13gallons.

Oddly, even though I know we have a 16gallon tank, I've never put more than 13.5g in, and my fuel light comes on at when I've only used like 11.5gallons.

My 1.8L is the same way with the gas light. However, I've gotten 42mpg with it and 502 miles on a single tank.

 

[98eclipseRS]

god damn i am jealous of all of you and the sad part is i have a non turbo wtf is that??? I realy realy need to reconsider the way i drive and start shifting sooner or something cause i dont get shit for gas mileage im gong to go with maybe 220 to a tank if im lucky i think the most i have gotten before is like 260 i guess i just need to chill with all the redlinning and stuff but even with a non turbo its so hard to do. Man this sucks.

 

[AWDriver]

21 mpg. on average both city/hi-way , not sure about full tank miles.

 

[Unleashed]

I get really bad carbon build up on my exhaust, like when i go and wash my car and maybe 2 miles ill drive and black carbon builds up quick..and i get reallly crappy gas mileage....anyone know why?

 

[CatLikeClaws]

mine has the same problem....i would also like to know why

 

[jpolizo]

Sounds like your running way too rich. You get lousy mileage and lots of carbon buildup. You'd probably also fail a smog test.

Sounds like the O2 sensor may be bad.

 

[Unleashed]

damn
i just replaced that thing 1 month ago too

 

[jpolizo]

Hmnnn; that's odd. Do you have one sensor or two? If you have two, the one causing the problem would be the front (closest to the engine) one.

The only other time a car has done this kind of thing to me was a non-DSM. That turned out to be the fuel pressure regulator which was running too much pressure; the thing was rich as hell.

 

[Unleashed]

Thanks man ill try the one towards the engine
i replaced the one near the cat
Ill get back to everyone on this

 

[jpolizo]

Cool man. The one in the back is a stupid thing that is basically so the ECU knows their's a functioning cat in the system (i.e. things should be cleaner downstream). The ECU uses the front O2 sensor to figure out how combustion is going.

Good luck!

 

[CatLikeClaws]

the thing in my case is i just passed emissions and had both o2's replaced, so i'll look into the FPR.

 

[rockice]

that might be my case i passed emissions and my o2 ground isnt hooked up

 

[BacknBlack92ESi]

I guess i get good gas milage, i rarly fill my tank up to full, just always 3/4 or 1/2 a tank. But i have a heavy foot, and when ever im all alone, no cars around, late at night, country roads, i have some fun , now my gas gauge doesnt work, I took my gauges apart to try to change the color of the needles, before i took the needles off, i had a full tank, now it says i have under 1/4 tank, and im only drove 72 miles on a full tank. wtf! it has to be my gauge, ill just drive until my gas light comes on

 

[DCsGST]

I usually get about 230-270 miles to a tank with city driving, although I don't know how I did it, but I got 350 on my last tank 220 of it was freeway thou.

 

[my95tsi]

Ok just recently i have been noticing some horrible gas mileage from my car. The most i get is about 14 mpg. It used to be alot better than that but i have been using my car for short trips around town lately. Actually i have only been using it only for that. I don't know why its so bad. This summer i put my catback on with testpipe, did my timing belt job, and lowered my car, thats it!! Oh and i got NGK bpr7es plugs gapped to .032 Is it the short trips that is killign that gas mileage? I checked my car 2 weeks ago and it had just over 14 gallons in it roughly. I set the trip odometer and now i'm just above 1/4 tank with 116 miles so far.

 

[ahner]

buy a toyota corolla.

 

[TSiAWD666]

Change your gap to .028". Verify that your O2 sensors are functioning, most importanly the first one. Check the grounding straps on your exhaust. Look for intake and exhaust leaks.

 

[bono316]

Have you cleaned/replaced your air filter lately?

 

[Defiant]

You may not be getting warm enough to keep your plugs happy. Try a set of 6's.