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

 

[SoCaliEclipse]

Eh, I am happy so far with the 20G putting out about 250 miles per tank. Half around town, half freeway. It works out to average about 20 mpg normally, so its not too bad considering the 20g and fuel pump. i am sure it will go to crap when i install my afc (sitting in the garage) and when I get my injectors

Brian

 

[JCG-GSX]

My car ranges between 20-24 MPG 50/50 highway city. Funny thing was when I was out of state I was getting 24-28 MPG. I guess I chalk it up to crappy 91 octane MTBE garbage we get in CA.

One other note, although the fuel capacity is 15.9, don't ever try to run it that low. I ran my car down 14.5 gallons, and she got pissed and shut down until I hiked my @ss to the nearest gas station and added in a gallon of fuel - no damn good!

 

[thumper]

Alright I just finished my rebuild on 1991 Eagle Talon Tsi AWD. I had the head rebuilt with new intake valves. They were all bent due to timing issues. Well I got the engine in time, and it runs well. However it seems to be getting poor gas mileage. 40-50 miles on a quarter tank of gas. It was empty and i filled it up with 94 octane the first day i drove it(yesterday). I didn't drive it today, because the valve cover is cracked, I'm going to JB weld it today after I get out of classes. Everything else looks alright. Is there any connections or sensors i might check to see if this is my problem, or does this seem like normal gas mileage for a turbo engine. I've never had one before. Thanks for the input guys.

 

[Defiant]

The "quarter tank" is a bit worrisome- do you mean ¼ as shown on the gauge, or a _real_ ¼ done with your tripmeter and actual gallons. Mine uses its first "¼" (on the gauge) in about 50 miles, but I'm getting a bit over 20mpg.

 

[thumper]

1/4 on the gauge. If that's the case i might be running about the same, and anything 20 or better is satisfactory to me. I'm VERY pleased with the performance, it seems to run strong. It's a kick in the a$$ compared to my 1.8l laser. I'm still proud of it evne though it's giving me problems. I know i can fix the crack in the valve cover easily. i guess i just don't want anything to be wrong with it i double checked everything on the rebuild, it was the first thing i ever did with a engine in my life
Thanks,
Proud DSMer

 

[TalonRacer18]

If its too bad, check your o2 sensor, they are probably fine but its worth checking them out.

 

[ravage_talon]

did you change your air filter and plugs after engine replacement?

The plugs can foul after and engine rebuild due to all the grease and the rings not seating right away.

 

[Defiant]

Yeh, use the tripmeter and actually figure your mileage.

You can probably fix the valve cover with some JB Weld, ONLY on the outside, and off the car. Covers are cheap and plentiful at the wreckers and on eBay.

 

[thumper]

alright new info. people are telling me that yesterday when i was leaving the lot on acceleration there was a puff of black smoke. It was BLACK not BLUE so that's a good thing. I guess, but is it posible that the set screw is not adjusted correctly on the TB. The car idles but it has a lump. just one when it idles what would cause this. I'm sorry for all the questions but i've never tuned anything before. I will make this run correctly and efficiently before i'm done. Thanks again for all the help.

 

[thehyena]

you may wanna get rid of the roof spoiler. thats the biggest problem i can see with your car

 

[thumper]

sorry but ur dissin the wrong car. I've got 2 DSM's One with show and one soon to have go thanks for the useless input though u ass

 

[TalonRacer18]

umm then why does it say you have a 91 talon tsi awd and then you have a picture of it with an apc ###ot spoiler on the roof

 

[Defiant]

How many miles have you put on this thing? The ECU takes a few hundred to get itself sorted out. Stop obsessing for a couple of weeks, give everything a chance to settle down. Just drive it and enjoy it a bit.

 

[Newlogics]

I get less then 16 most of the time...

57 trim Mutt, 660s, SAFC and Walboro 255 are my fuel mods...

But then again, I sees more boost then vacuum

 

[1badgsx]

about 14mpg
18psi on FP-30
850's
255lph hp
93 octane non-oxygenated

 

[MTgzepplin]

I have a 90 eagle talon tsi AWD and i only get about 180 milles to a tank. My friend says he gets way more. The fuel pump on my car has been going out for quite some time. Is this a possible cause? Otherwise what could be doing it.

 

[MTgzepplin]

could it be the o2 sensor going out? the check engine light is on a lot and when the turbo spools higher it shuts off

 

[rivet0r]

I'm currently dealing with the same gas milage as you.. 180 to the tank, and no fix yet. It can be plenty of things, but unfortunetly it's pretty much process of elimination. I would start by getting your CEL codes checked out and take it from there.

 

[echo]

i get about 244-252 to a full tank of gas. not bad i guess.

 

[Thebeast431]

180 Tank. I wish I was getting that much. I get about 160/tank. Ends up being about 13-14mpg city/highway or 16 on the highway. I put in new 02's, no difference, new plugs with right gap, new wires, new air filter, still no difference. No big deal, you didn't buy the car for the good gas mileage.

Travis

 

[Tallen]

are u venting to the atmosphere?

 

[slowlaserRS]

some times I get 240 a tank other time 300 some on once in a blue moon I all most got 400 to a tank.

 

[davin24]

just a thought but low tire pressure can make a huge diff.
just an idea

 

[MTgzepplin]

Thanks everyone for the ideas ill check them out, i think i am just gonna get my codes checked or whatever
How much does one of those CEL testers cost and where could you buy one?

 

[FourG63 97GST]

i got 19mpg this week.
I guess thats good for the way I drive