Honestly - what is your mpg???

[snakepitt1]

I have a 2003 Touring Edition. I have installed a free flow intake a magnaflow muffler, Screamin Demon coil, Magnecore wires and Double platinum plugs, oh, and lowered it. I also have 79945 miles on the car. I have kept track of my milage since I bought the car ne in Sept of 2003. I have averaged 23.54 miles per gallon over all. I have seen a high of 26.25 MPG. I found that with the sunroof fully open and the rear windows cracked, milage increases. I am running 44PSI in all 4 tires, I use only Mobile 1 full synthetic oil. Oil changed every 3000 miles.

[Ken Swenson]

Interesting read. I am disappointed with my MPG. I have a 2003 Limited with an automatic. I keep a very accurate gasoline history and calculate the cumulative miles per gallon, which is the total miles divided by the total gallons of gasoline put into the car. The car peaked at 21.92 mpg just before the dealer 30k service! Today it is 21.72 mpg at 38600 on the odometer and slowly decreasing.

[quicksilverdon]

quote:Originally posted by BumperBob

... the gas mileage was much better if the tank was kept fuller. By this I mean if I filled up the tank when it got down to between 1/2 and 3/4 full, the mileage would average between 24-26 MPG. If I let the tank get down to 1/4 full before filling, the milage woould be closer to 20 and if I let the tank drop below 1/4 the mileage would be down into the teens....

Any idea why this might happen? [:I] I thought I was nuts, and that I wasn't watching close enough when I noticed this trend. I didn't catch the relationship between how full the tank was to the actual mileage I got until you wrote that though. But now that I think about it, I've seen the same thing in my '03 automatic.

Gas costing what it does now, I'll be filling up more often to get the most out of a tank! I'll be keeping a closer watch on the results for a while to see if it pans out.
[?]

I beleive it has to do with evaporation. There is less air space in a full tank for gas to evaporate. My theory, but I see the same variation.

I just calculated my mileage, over the last 2,500+ miles:
25.47! It was at 22.45 overall before. I've been accelerating more gradually and trying to get into top gear as soon as I can, and not using cruise on hills (less downshifting), but still move at quite a good clip, just don't zoom up to speed.
I really don't think you can go mileage by tankfull - I see too much variation - I get 30 MPG on one tank, next will be 21, etc, yet my driving is the same - so I measure over a longer stretch to figure real mileage.

[Capt Kidd]

[8)]I just finsihed installing Stage One on my 05 GT ragtop and this weekend will be the first road trip with it. I've heard it is supposed to give you not only more power, and it does, but also better mileage.

Has anyone else checked mileage after Stage One?

[Ray]

I have 2005 Touring 5-speed and get 19-25 mpg ...

[robinjoe]

I always look at two or three mileage readings together when assessing my mileage. If I don't quite fill the tank before a trip and maybe over-fill it after a trip, it can give the impression of much lower gas mileage than actual.

I too have recorded every fill-up, and my average over 18 months is 19.9 MPG. My 2003 GT has 33,000 miles on it and it is my daily driver. Most of my driving is stop and go in heavy suburban commuter traffic. I tend to be a lead-foot with jack-rabbit starts. Usually when I hit the open highway I drive 70 to 80 MPH.

My best tank so far (that doesn't apear to be an anomoly due to fill-up errors) was 24.3 MPG during a long trip from Virginia to Maine. During that trip the fill ups showed:
17.9 before the trip (probably over-filled tank)
24.7 probably an anomoly due to previous over-filled tank
21.4
24.3
20.4
22.1

If I discard the 17.9 I get 22.6 MPG, but I don't think that is accurate since the first two are anomolies
Discarding the first two anomolies, that trip averaged 22 MPG.
Including the first two, the average is 21.8, very close to 22. The low 17.9 cancels out the high 24.7.

All were with 93 Octane Costco gas.

Joe

[worlddreams]

28-31 mpg average highway and city combined. Regularly use Acetone http://www.google.com/search?hl=en&q...in+gas&spell=1 in my gas as an addative.

[Hooligan]

Just bought a 2006 NA and on the highway with 2500 miles on it, in one streach between fill ups I got 27. I did replace the stock plugs with platnum and put on MOPAR preformance wires because of a slight miss when I had 1400 miles on it. I'M HAPPY!!!
17 -19 around the city because I have a heavy foot.

[philpatton]

Like most everyone else the low MPG is a disappointment.

I just bought a ’04 that had 22K on it when I bought it and only managed to get 14 MPG.

I read some suggestions on different forums and switched to synthetic oil, added a cold intake system, put in new plugs and Crane wires, run the tires at 32 psi and have managed to get it up to 25 MPG.

I’m still tinkering and figure that there should be another 3-4 MPG in there somewhere.
[8]

[GR8FLPT]

Check your sparkplugs. A buddy of mine was having the same problems. We regapped his stock plugs to .040 (turbo) & he got an instant 3 mpg.Also, 3 out of the 4 plugs I could remove by hand, cause they were so loose from the dealership.