Gas mileage for a grand prix gtp

RobAhr24 · 05-09-2007, 01:26 PM

What kind of gas mileage are you getting in a grand prix gtp? city and highway....

edy figueroa · 05-09-2007, 01:45 PM

My 97 GTP gets 18+/-city and 25+/-highway.

BNaylor · 05-09-2007, 05:50 PM

Before mods I got around 17-19 in city and 25+ highway depending on the cruising speed normally 70 mph and above.

duffman87 · 05-09-2007, 11:06 PM

thats what i get in a 2002 gtp but i currently found out how to get about 20-22 city and 25 highway.

keep the car in 3rd gear which is pretty much over drive off. when the car hits 55 and you know you wont slow down then shift into drive which is overdrive. right now i am getting about 20.5 and 22 if i drive nice which is rare. lol and at every take off shift back in to 3rd. it does not ruin the transmission because its all electronic and you will have smoother shifts also. i leave my car in 3rd gear until i pretty much hit the toll way which is not often. where i live im only going 55 for maybe 5 min max and i found that i save gas in 3rd. give it a shot and tell me if it works for u. its working for me and my buddy and my dad in his f150 but thats different.

Zepguy · 05-12-2007, 12:22 PM

In my 2005 GTP my daily commute is about 1/3 freeway (70 MPH+)and 2/3 city. I get a disappointing 18-19 MPG... and have for the past 2 years.

I was about to start a post when i saw this one. Any suggestions (aside from losing some lead from my foot) on ways to get better MPG? Any mods that will do this?

I may try the 3rd gear suggestion mentioned above, but I'm trying to figure out the principle behind it, and why that would work. And i'm not sure it would work on a 2005. Does the engine use more gas when accelerating at low RPM's?

DJ JEFF · 05-13-2007, 01:06 AM

I commute 100 miles a day in my 97GTP. All frwy. 2k a month. 183k on it currently I get a constant 29-30 on the frwy and 24-25 in town. If I don't burn premium my mileage drops off considerably. Unless an emergency I only burn premium cause for one your suppose to in these cars and 2 if you don't you end paying out that extra money you save buying the cheaper stuff, in mileage anyway. My GPT has been having acceleration issues for awhile, getting a bad shutter under load. But my mileage hasn't dropped off at all since this started happening though.

BNaylor · 05-13-2007, 10:48 AM

Quote:

Originally Posted by Zepguy

In my 2005 GTP my daily commute is about 1/3 freeway (70 MPH+)and 2/3 city. I get a disappointing 18-19 MPG... and have for the past 2 years.

I was about to start a post when i saw this one. Any suggestions (aside from losing some lead from my foot) on ways to get better MPG? Any mods that will do this?

I may try the 3rd gear suggestion mentioned above, but I'm trying to figure out the principle behind it, and why that would work. And i'm not sure it would work on a 2005. Does the engine use more gas when accelerating at low RPM's?

We get alot of complaints on '04 and up models getting poor gas mileage versus the '97-'03 models. But the general concensus is lead foot = poor fuel economy. Now on certain GTP/Comp G models one expanation maybe the final drive ratio. '97-'03 L67 models have a 2.93:1 final drive ratio. Many '04 and up were delivered with 3.29:1 so you would want to check the differential option at delivery.

Personally I don't see any advantage of keeping the car in 3rd gear versus 4th - overdrive or letting it do the work automatically. And there are too many variables involved to include terrain and types of roads traveled. But it may work for others.

Engines will always use more gas accelerating whether light, moderate or heavy. Reason is the PCM module switches to open loop mode for fuel injection metering, control or management. In closed loop mode the fuel injection system relies primarily on the front 02 sensor for helping control and keeping air/fuel ratio at the ideal 14.7:1 ratio.

edy figueroa · 05-13-2007, 10:08 PM

I flushed the radiator,put a gallon of Pro Blend Ice Water street version and really noticed a much better MPG from 24+/- up to a 28+/- highway MPG.Its been like that steady everyday for the past week! Also my 97 GTP is running much cooler now. So i think that keeping lower engine temps helps too!

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