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

 

[diamondstar36]

Could be caused by a few things. If your O2 sensor goes out, the car will go straight rich to keep the car alive. It'll gum up your valves, smoke, stumble, and get horrid milage. Also are you sure it's stock? An aftermarket fuel pump (especially a whinebro 255) will suck gas pretty bad.

 

[rubbersidedown]

i don't know of many sports cars that get good gas mileage...

 

[OmegaGS-T]

Originally posted by Psycron
so AWD sips more gas than FWD? My FWD was getting like 275-300 a tank. Is there anything I can do to get better mileage? S-AFC maybe? Seems like the computer is inefficient in mixing the air/fuel ratio. FWD must also hold more fuel than the AWD tank. My turbo doesn't spool until about 4k, maybe that has something to do with it (housing has some cracks in it)?

basically an awd should have worse gas mileage becuase A it's heavier B the gearing and what it takes to push the drivetrain. also try not getting in to boost... that'll help your mileage.

 

[KRAB]

With my car I'm getting just under 24 miles/gallon. This is mainly city driving and I also have to let my car warm up for about 10 minutes before driving it. Gotta hate winter.

 

[nine5raptor]

i'm pretty good at getting right around 17 mpg. oh yeah!

 

[Enigma_Man]

I get about 22 mpg, mostly highway driving.

I also have a brand new O2 sensor (just replaced it, to bump up from the 15 mpg I was getting before)

-Jesse

 

[Psycron]

Originally posted by rubbersidedown
i don't know of many sports cars that get good gas mileage...

:laugh:

You have a point there, the need for speed comes at a price...MPG!

Maybe it could be the o2 sensor, if anyone suggestions of a good means to check it, by all means post...I wanna hear it.

My car runs pretty good, I've got so many little things wrong it's almost ridiculous. Fog Switch/Power Mirrors/Cig Lighter don't work, and the wire with the metal piece that goes to the rear defroster isn't hooked up. Rear wiper doesn't work, and the fronts move around unnaturally but still work. there's a gash in the dash on the passenger side, and there's no floor mats. Change holder-thing is missing, the little square flip-up door next to it is broken, too. The last person that owned this car was a real SH!T.
It doesn't like to start in really cold weather, though. RR RR RR RR RR RR RRRRRR is what it sounds like when the temp is near zero =)

I don't care. I love my DSM. I want a 2g so I have the best of both worlds!

 

[roadtalontsi]

z 15mpg is bad. You guys are funny. I avg like 17 in my talon fwd turbo. Come on complaining about like 17+mpg shouldn't be occuring. Its turbo. im sure if i ragged on my car for a full tank i could probably get into lower then 10mpg. My truck gets 7mpg driving slowly. Thats why i got this car for economy. Note: My truck cant out run civics and its lifted w/ 35" tires hehe

 

[greyforestgst]

im always over 20

23 right about now. highest i got was almost 30. my o2 sensor is ####ed again i think. i dont care though, let it run rich; big16g is pushing more air anyway.

 

[markGSX]

I still have the original window sticker for my GSX and I believe it's rated 19 MPG city. I get about 17 mpg, but mines not stock and I'm addicted to boost.

 

[Psycron]

There's probably nothing wrong with my car. Boost is like a gf that wants to give you head. How are you supposed to say no?

I guess I'll lay off it a little. Isn't it surprising that a 4-cyl gets such low mpg? With the turbo we must be burning close to what some v-8 guys do under normal driving. ah well, 19 mpg it is.

 

[echo]

i get 244 to a full take of gas EVERY FRIGGIN' time. i can't get away from that number. maybe she is trying to tell me something. , i'm gonna try it for lottery or something like that.

 

[2-0turbo]

10 MPG on the track, ~18 in the city, best of 26 on the highway (all on 14B turbo).

 

[rubbersidedown]

Originally posted by Psycron
Boost is like a gf that wants to give you head. How are you supposed to say no?

True... but the downside to having more boost is lower gas mileage... what's the downside to having a gf that wants to give you head all the time? I believe you're missing something in your comparison.

 

[DrivnMastr]

Originally posted by Psycron
Ok, here's the deal...I bought my 92 Laser AWD about a month ago and I'm slowly fixing all the probs with it. The latest problem is my mileage -I swear a mustang V8 gets better mpg than I do! I drove about 80-100 miles and burned half a tank of gas. Are AWD tanks smaller? Even with freeway miles I'm still getting 250 to the tank.

Could it be my o2 sensor going south or something? Car seems to run fine. If my mpg is this bad right now, I can imagine what it'll be when I get an L1R

i get 250-300 miles a tank less when i get boost happy our tanks our 15 gallons read the owners manual when you boost the fuel pressure regulator opens fully to supply the motor with enough fuel so it does not run lean

 

[roadtalontsi]

Originally posted by rubbersidedown


True... but the downside to having more boost is lower gas mileage... what's the downside to having a gf that wants to give you head all the time? I believe you're missing something in your comparison.

You have to put up w/ her constant crap...telling you that you drive to fast, or that she wants to drive and how you need to see her more often and she likes the cute guy next door z

 

[rubbersidedown]

well that's in general w/ all girl friends... but not all want to give you head all the time... the ones that do want to give head want to give it to everyone else too. i'm just saying what's the downside to having a gf that would actually want to go down on you and only you all the time?

 

[Shane818]

Hey i think something is wrong, 32 miles to a quater tank. 132 to a full tank of gas? the car is turbo and has 145,000 miles. whats going on here? my friend says he gets at least 200 miles to the tank in his turbo....what should i check? I used fuel injector cleaner, did a tune up. but am running out of idea's.

 

[rubbersidedown]

O2 sensor maybe? do a compression check on the cylinders.. i think that has something to do w/ it. heh

 

[eXploitedGST]

yae its most likely ur o2 sensor... my talon and eclipse both had bad gas milage til i fixed it.... also if u run open bov itll get bad milage and ruin ur o2

 

[Shane818]

ok thanks guys. i dont have a BOV yet but was in the market for one after i do some head work.

 

[jbillakdsm]

Your 02 sensor may just have a lot of carbon build-up on it. My advise is to run some BP high-test in you car for like 2 full gas tanks and see what happens. I was talking with a chemist for BP and they put an additive in that helps remove carbon from the exhaust track. My car was doing the same thing your is and it worked for me. I now get around 200 for 3/4 of a tank (10 gallons). Granted I drive faster than most, so I should get in the 23-25 range if I baby it.

 

[RocketDSM]

160miles per topped off really full tank. I drive about 75-85mph 90% of the time. I use 91oct (best I can get on a regular basis). I've tried cleaning the injectors, replaced both O2 sensors. When I bought the car I was getting about 200-220 to a tank. I put on my mods, dropped to 130. I've got it worked back up to 160 through driving over the course of a year. The cleaning and replacing made no difference at the time. Watching my cheap wanna-be Autometer A/F guage, I bounce around the "normal" zone like a normal non-modded car. I'm stumped and so far everyone else has been too. If someone knows something new, please pass it on.

 

[Golden4g63child]

Either it's the o2 sensor and or any fuel related components. I swapped out my old fuel filter 6 months ago and pour in some fuel injector cleaner at every oil change, and I get 370 to a full tank (I have 118,000 miles by the way) now.

 

[pneumo]

It almost sounds like your gas tank or something is leaking. Brakes dragging? Mismatched tires or tire pressure will suck up more gas in an AWD car because of the viscous coupling constantly turning.