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

 

[ADrewzki]

Not to be rude or anything, but this topic has been discussed time and time again. It's not how many miles per tank you THINK you're getting. It's how many miles to the gallon you get that's important. For instance, my fuel light will come on when I have a 1/4 tank left. Why? Hell if I know but it does. When I fill up though, it only takes about 9-10 gallons and after a little magic known as MATH, it comes out to about 20 mpg. Like a post already stated, bad O2 could give you bad gas mileage.

 

[Qckrun]

I was wondering if anyone knew what kind of gas mileage 98' Eclipse's get? I am thinking about getting one, but my main concern is gas mileage.

Any help is appreciated, and I am new here so please dont be to hard on me .

Thanks guys,
Qckrun

 

[siceclipse]

turbo or non turbo?

 

[blvngd86]

my gst got 21 when i first got it. i put a K&N filter in and i've gotten 24 ever since.

 

[Crawl]

Just bought a 95 GSX and I feel like im gettin around 15. I fill the tank up and the gas is gone before I get started . Going to measure tonight to see exactly what im getting.

 

[lngbrdr]

I get 20 in the city and 25 on the highway. I do have a K&N FIPK though.

 

[Nanan]

I get 20-22 mpg on avg with regular driving, if I ride hard then it can drop to 15ish mpg.

 

[punishercb]

hey lngbrdr, i noticed that you have a gst too. Do you have anything else done to your car besides a air filter? I'm gettin my gst this weekend and I'm also curious about what kind of mileage I'll get. It's a 5 speed so I'm hopin that will help.

 

[PieEyedPiper]

I get 300 miles to the tank, if that helps. havent calculated my mpg.

 

[L2RTSiAWD]

It says to do a keyword search before you post a thread. A good idea since this has been disccussed many times.

Here's a start.

http://www.dsmtuners.com/forums/showthread.php?t=11241&highlight=gas+mileage

 

[XakEp]

I went and bought a 700$ Geo that gets 50mpg. Saved me alot in gas prices.

 

[sweet97]

Again. Hook up the EGR if it has been disabled. Mark

 

[90blacktsiawd]

I noticed nobody has suggested change your fuel filter yet. It wont make a world of difference but maybe an extra 25 miles to a tank or so.

 

[qwik59]

Damn, looks like I'm kinda glad I didn't swap a turbo setup into my brothers RS, I get like 35mpg on the highway with that SOB. Shoot, even my AWD 5.9 Grand Cherokee is getting better mpg's than some of you guys, like 21mpg on the highway and 17 in the city. Almost sounds like you're bleeding off some serious boost. If you've already tried checking over all the ignition components and they're up to par as well as your wastegate etc., I'd stick it on a wideband and make sure it's not running crazy rich.

 

[tsi_daggie]

Again. Hook up the EGR if it has been disabled. Mark

i did a block off on my egr and i am running 19.5 mpg same as before i did it. and that gas average was over 700 miles, not just 1 tank.

but every car is different

 

[BOOSTING_GST]

So what they are saying in the link above is for us to get a ground wire and bolt one end to the chassis and the other to the motor (heat shield bolts)

 

[LookDadNoBdyKit]

Im getting around 140-150/tank

What I've done:

New plugs
New wires
New o2 sensor
New fuel filter

I am stumped as to why its getting this bad of gas milage. I took it easy driving the car without boosting rarely or at all and it went from 100-140. It should still be getting a lot more than that though. There is no issues with coldstart/coolant temp sensor etc.

Any ideas as to what to look for/replace/check for on the logger?

 

[jfdid]

How many gallons are you pumping at each fill up? Sounds like a newbie question, I know, but it may be just your gas gauge.

Check it out and do the math. Good luck.

 

[Defiant]

Don't even think about talking mileage unless it's in Miles Per Gallon.

"Per tank" means shit.

 

[Omega]

Check the timing, condition of the cat (could be clogged). How does the car run? Is it quick or is it lacking in power?

 

[86MCSS]

Well I get anywhere from 200 to 220 miles per tank or sometimes less depending on how I drive the car. And it usually takes about 11 gallons to fill me back up, so if I get 220 miles out of my tank Im doing about 20 mpg. Not bad if you ask me. I could do better but my foot wont allow it

 

[LookDadNoBdyKit]

I fill up ~12.x gallons.

no cat - i have a strait pipe. timing is correct

car is running pretty quick

 

[Omega]

Perhaps you're running waaay rich then? How are you tuning, WB, dyno, what?

Also, check the coilpack.. weak spark, incomplete burn.


I have a similar setup and compared to when I first bought the car, I get BETTER bas milage. I do contribute that to the turbo not spooling up as high/as often.

Back to the basics though.. possible fuel leak or a whacky fuel gauge. Are you sure you are in need of fuel when the gauge says so?

 

[LookDadNoBdyKit]

how would i test the fuel gauge?

im tuning via logger

 

[Defiant]

I'd said no "Per Tank" values.

Closed.