Pontiac Grand Prix Engine Poor Mileage

After Changing And Overfilling My Crankcase By A Quart Of Oil And Taking A 450 Mile Trip With It Overfilled. I Started Having Poor Mileage...

I Have A 2004 Pontiac Grand Prix With 40,000 Miles. The Emmission Light Came On And Is Staying On Solid. I Read The Owners Manual And...

I Have A Question Regarding Our `02 Grand Prix. Normally We Get Around 25-34mpg Or 400-425 Miles On A Tank Of Gas And Recently We Have...

Hi. My 2001 Grand Prix Has 230,000 Miles On It And Still Runs Well. Lately I Have Noticed That My In-town Gas Mileage Has Been Awful. If I...

2001 Pontiac Grand Prix 6 Cyl Front Wheel Drive Automatic 114 Km Miles My Grand Prix Sat For Two And A Half Years. I Changed All Plugs...

My Car Gets The Gas Mileage It Should From Full To About 3/4ths A Tank From 3/4ths To Half I Get Maybe 20 Miles And Then From Half To A...

I Have A 1999 Grand Prix 3.8 That Is Not Supercharged. Im Getting 13 Mpg With It And I Know It Should Be Much Higher Than That. The Car Runs...

I Have Seen Some Of These Performance Chips That Are Claimed To Boost Torque And Mpg, Do Any Of These Actually Work Or Worth It? I Have Seen...

I Have Experienced A Significant Loss Of Fuel Economy. Egr Valve Is Good, Mass Air Flow Is Good, No Fuel Leaks, Fuel Pressure Regulator Is...

My Car Is Using Hundred Miles Per Tank Less Than I Was Getting A Few Has No Kickdown Power Will Not Get Up And Go Other Than That Runs Fine...