Something's up with my car
12-01-2010, 02:35 AM
#22
5th Gear Member
Join Date: Sep 2006
Location: CA
Posts: 4,039
Teej, your t-stat might be stuck open as other have suggested. You should be higher than that unless you are doing laps at the north pole or something. How long does it take for the car to get up to that temp from a cold start-up? If you can datalog, see what your actual coolant temp is at and not just what the gauge says. The factory gauges can be less than accurate to say the least.
12-01-2010, 05:41 AM
#23
The 99-04 GTs have 281ci motors not 289ci
12-01-2010, 09:35 AM
#24
3rd Gear Member
Join Date: Apr 2008
Location: New York
Posts: 990
Well were you on cruise control? And I keep my highway to under 72mph. I usually stick around 65mph, because there is research done that suggests that for every 5mph over 65 you go, you drop 1mpg off. That wouldnt make that much difference, but my fuel filter was changed around 30k ago, which needs replaced again now I think. I usually check my gas mileage and dont get over 20mpg whether it be city or highway or mix. Now if its purely highway I might be lucky and get like 23-24mpg, but nothing like the 27mpg i used to get right after I changed the fuel filter.
12-01-2010, 09:46 AM
#25
Change your fuel filter and seafoam that thing. Also, run some injector cleaner through it too. When i changed my fuel filter, I picked up 3mpg. Started getting 18mpg instead of around 15 myself. Then changing my driving style and shifting at 2200rpm or less, and just driving sanely makes a world of difference.
12-01-2010, 10:28 AM
#28
5th Gear Member
Join Date: Nov 2005
Location: MN
Posts: 4,412
12-01-2010, 12:34 PM
#30
5th Gear Member
Join Date: Sep 2009
Location: KY, was MA
Posts: 2,797
Well were you on cruise control? And I keep my highway to under 72mph. I usually stick around 65mph, because there is research done that suggests that for every 5mph over 65 you go, you drop 1mpg off. That wouldnt make that much difference, but my fuel filter was changed around 30k ago, which needs replaced again now I think. I usually check my gas mileage and dont get over 20mpg whether it be city or highway or mix. Now if its purely highway I might be lucky and get like 23-24mpg, but nothing like the 27mpg i used to get right after I changed the fuel filter.
I also drove my mothers 02 Cadillac cts or dts whatever the hell it is and I would get better mpg's NOT going 65...again more like 70ish