'99 Grand Am only getting 17mpg???

I was wondering if some one could tell me why im only getting 17mpg because at my local car lot there is the same exact car as mine and its rated at 27mpg. I have a '99 grand am gt with 109,000 miles, the only mod i have is a cold air intake with a k&n cone filter and the spark plugs and wires have been replaced. Recently i have been taking it alot slower because of gas prices but im still getting only about 17-19mpg. Shouldnt i be getting a lot more than that?

hello brots06. my 99 ga se 3.4 has been modified alittle and i get 21-25mpg in city/town driving/cruzzing just depends on if the AC is on or if i'm dog'n on it hard. this car has 120k+ mile now. On the highway i get 365mile on 11 gal of gas.
You say you changed the plugs/wires? May try changing the O2 sensors. 17mpg is bad! i hav a 76'cutlas w/455 rocket and it get 15-18mpg in town on highway 18-20mpg.
just keep ur foot out of it, that'll help tooo. if u hav other questions just holler.

Can i bring my car to a local shop and have them check the sensor to see if its bad? How much does a new one with install typically cost? And could that be the only problem?

Sure can hav it checked. I beleive they,(there are two O2 sensors) run about 85$ each. So yes I would have them checked before replacing. Hav you done anything on the fuel side, like change fuel filter? periodicly running some injector cleaner, or even go for the professional cleaning by a Gm dealer or other qualified shop(around$200), cleans all the carbon build up in the engine.

Keep the air cleaner clean. Change oil every 3000-4000 miles helps with fuel economy. I can tell when it is close for the oil change becuase the Mpg starts droping. It is the little things that kill.

I was wondering if some one could tell me why im only getting 17mpg because at my local car lot there is the same exact car as mine and its rated at 27mpg. I have a '99 grand am gt with 109,000 miles, the only mod i have is a cold air intake with a k&n cone filter and the spark plugs and wires have been replaced. Recently i have been taking it alot slower because of gas prices but im still getting only about 17-19mpg. Shouldnt i be getting a lot more than that?


brots,
what plugs and wires did you use?
were you getting better mpg before the swap?
if you put a plain copper resistor or just a regular platinum, you actually downgraded from what GM had stock in there.
the AC plugs you pulled out: 41-601? 41-602?
are basically a double platinum/RapidFire plug.
designed for certain GM powerplants to combine the best of both worlds:
a hot plug when needed (stop and go traffic, and high miles)
a cold plug (highway, when your foot mashes the floor)
and designed for about 70-100K worth of wear and tear.
the others could be right, I mean check your sensors (pull them and clean them), and pull and clean the IAC and/or EGR;
but an O2 sensor is $40-60?, and you have no engine light.
a plug swap back to OEM is $30-40. and see if the mileage comes back.

hope this helps,
chris
nrt racing

Sure can hav it checked. I beleive they,(there are two O2 sensors) run about 85$ each. So yes I would have them checked before replacing. Hav you done anything on the fuel side, like change fuel filter? periodicly running some injector cleaner, or even go for the professional cleaning by a Gm dealer or other qualified shop(around$200), cleans all the carbon build up in the engine.

Keep the air cleaner clean. Change oil every 3000-4000 miles helps with fuel economy. I can tell when it is close for the oil change becuase the Mpg starts droping. It is the little things that kill.

xero is RIGHT ON track here.
fuel delivery! if the plugs are good, the wires are name brand of AT LEAST 7-8mm, has the other maintanance been pulled?
if you don't want to have the injectors/rails/lines professionally done,
dump in some higher dollar fuel system cleaner into the tank, when it is only half full. more concentration. still not as good, as having the system pressurized and blown out, but anything helps.
you should be getting a minimum of 22-26mpg, even WITH your miles.
I have a 2.8L GM throttle body engine with over 180,000miles, and when I slip below 26mpg(and I'm a leadfoot), I'm griping!

i tried those regular Rapid Fires and they melted the tops off in about 10k mls. So i went to the AC Delco Iradium plug, what GM recommends, w/Bosh 8mm wires. Nothing fancy, but I'm lookin for Economy not HPs. Good Luck brots06

I just went out and looked the the wires for the plugs, alls they say is standard 7mm. So when i bring my car in just tell them i want the O2 sensors checked, right?

I just went out and looked the the wires for the plugs, alls they say is standard 7mm. So when i bring my car in just tell them i want the O2 sensors checked, right?


7 mm is stock GM i believe. Any Name brand wires. 8 mm is a good replacment. Unless youre doing any drag racing on the weekends.

They'll know what you are talking about when you say O2 sensor, and it can be tested to see if it operating in normal range. Seeing you hav a 99' its probley about time to change them, and you should notice a difference in Mpgs and we all need more mpg.