Fuel Economy

[kels1216]

I bought my 02 Grand am in May. The first month I had it I took it on a little road trip. I seemed to get about 650km to the tank. Highway Km. Now it seems that if I get 550 or 500 I am doing good. What do you think the problem could be? The car just turned 100,000Km. I had it in for a tune up and they said everything was fine. Do you think the plugs should be changed. I heard that bad plugs will kill the fuel economy

[jayhawk]

Yes, yes they will. Personally I think GM boasting of 100,000 mile plugs is bull.

[tenspeed]

I would take it one step at a time. First, start recording how far and how much fuel you're using. Trying to gauge improvements by the tank is not close enough to see much of a difference. Run a couple tanks of normal driving to see how many MPG (KPL?) you're actually getting.

You can do the simple things like inflate your tires and replace your air filter without too much expense. Another factor that you can not control is the temperature. Longer warm ups, pushing through snow and the softer tires from the cold will increase your fuel use. I would replace your plugs last to see if it actually helps.

My 2.2L/ 5 speed usually gets between 30 - 32 MPG in the summer and a little less than 30 in the winter. It has 35,000 miles and I usually drive 40 miles each way to work. Half highway and half rural roads.

[Texican]

We're getting under 20mpg in our automatic. I checked the codes and got an O2 code (P0130). I cleared the code and I'm waiting to see if it comes back or if the milage improves.

I've found (in a different car) that I can dramatically improve milage by over-inflating my tires by a whopping 5psi. Not that I'm telling you to over-inflate your tires. Mine are rated for a much higher psi.

[XtremeGrandAm]

I have always gotten bellow average gas mileage in my Grand Am even after having the O2 sensors replaced.