I just got back from a 400 Mile round trip (Virginia Beach to Durham, NC and back) and I averaged 22.4 MPG for the entire trip. Car is a Brembo equipped GT Premium w/3.73 diff. FWIW I took US-58 to US I-85 out and back for those of you who now the region. On 58 you can only really do about 62MPH tops otherwise one will be contributing to the local coffers. I-85 - you can boogie, I ran about 78-80MPH on it.

One note, after about mile 300 in the brembo equipped car, my lower back was killing me. This car is very, very, stiff and truly not a long distance cruiser.

 

Have you tried to skip-shift the gears? Like go 1-3-5-6 or 1-2-4-6... There is enough torque in these engines to allow for that when granny-driving it. Having the A/C on at all will always put more strain on the engine and yield worse mileage, especially in the city. Actually using "Max AC" is more efficient than regular because it recirculates the cold air keeping it colder and cycling the compressor less often. Other than that, I have noticed that gas bought at either BP or Mobil always yields better mileage than other stations.

 

+1 on BP gas getting better mileage . . . I've tried 3 or 4 different gas stations now and BP is always 1-2 MPG better

 

I was just using the dashboard readout. I'll calculate manually. Hope you're right.

 

Thanks for the BP advice, everyone. Good to know. I've been using mostly Shell, so I'll try switching.

 

I drive moderately aggressively and don't baby my car but around town get 18 - 19 if I keep my foot out of it.... 16 - 17 if I don't

 

15 in the city and 23.5 on the Interstate @ 80 mph. The car is an auto with 3800 miles.
I use BP, Shell or Chevron 93 octane. I keep my foot to the floor as much as possible.

 

On every fillup since my '05 GT was new, I reset the trip odo, gallons used, avg mpg, and avg mph. I stopped checking the mpg after about 20 times because it was always the exact figure. The gallons used is always exact too. I have checked the mpg with a calculator maybe a dozen times since, and it is still always exact. Maybe I have an abnormally good computer in my car.

As far as city/highway mileage, city mileage can mean different things depending where you live and what kind of traffic you deal with. If you're stuck in traffic and not moving, you're getting 0 mpg no matter what kind of car you have. Around my town, my average speed is about 24 mph. At this average, I usually get 16 mpg. Around town I aim for the best economy by accelerating slowly and upshifting as quickly as I can without lugging the engine.

A couple years ago when I had a longer commute that was 75% highway, the average speed was about 42 mph, and the avg fuel economy jumped to 20 mpg. My best mileage ever on a full tank since owning the car was 27.1 when I filled up before entering a highway, and filled up again on exiting 3 hours later. That average speed was 67. I think it all depends on your average speed (and of course your driving habits).

 

I just did a 240 mile round trip drive today all highway. I've always used my dash read out until I read your post. My dash said 22.1, when calculated manually was 23.6mpg. That's really refreshing knowing my mileage isn't so bad afterall. And btw, I have 3.73's and drove 80mph with the a/c crankin. Not bad!

 

Please explain how you accurately calculated the mpg manually? You would have to know exactly how much fuel was used. :waiting for reply:

 

Before my trip I filled up at my usual Shell. I don't top off ever. Reset my mpg n trip. When I got close to home I filled up at the same station n pump, again not topping off. I took my mileage driven and divided by the amount of gas at re-fill. That's how I calculated 23.6mpg. I figured that was about as accurate as I can get.

 

http://www.youtube.com/watch?v=PlT7L...e_gdata_player

 

That video is weird, looking at the reflection you feel like he's going in reverse. Oh and did he check the pressure in the the tires before he started this?