2006 Grand Prix
50k miles
Naturally Aspirated
I'm writing on behalf of a friend who is experiencing great pain at the pump due to the cost of fuel and poor fuel economy on his 2006 Grand Prix. Highway fuel economy has gone down from 25 mpg when it was new to 22 mpg. He is religious about keeping the tire pressure at 41 psi so we can eliminate that out of the equation. The car is stock, no Check Engine Light comes up and the engine runs good. What should be look into and/or replaced to restore the better fuel economy?
Also, are there any worthwhile modifications that can be done such as better flowing mufflers or chips to make it less thirsty?
