xtn

I found that the car gas meter is actually very accurate, which I wasn't expecting. I calculated gas mileage by dividing gas put in by miles driven. I drove easy using cruise control 90% of the time at 70-75mph and pounded first through third about twice each way. Car is a 13' GT speed all stock.

* NJ to FL the car did 26mpg (actual) while the cars computer showed 25.9. With total of three occupants including myself.

*On the way back from FL I rode loaded with a total of 4 occupants including myself and a trunkful of luggage. The car did 26.5 mpg.

*Total round trip cost me right around 280.00. I've done this trip many times before and in 2011 I paid approximately 240.00 round trip in a 2010 4 cylinder Honda Accord! It's worth the extra 40.00 :-D

Comfort is another story. I was fine, but my passengers had some complaints haha


Shot of the trunk and suspension

griffojm

Pretty amazing efficiency for 400+ HP. How many miles are on the odometer, if you don't mind me asking?

Nuke

Highway cruising can be provide some amazing fuel mileage for a performance engine. What gears are you running?

My GT has seen quite a few 1000+ one-way miles trips in addition to countless 900 mile round trips, so I have tons of data (I've been hand calculating fuel mileage since 1977). With my set-up in my GT, anything over 70 MPH will average increasingly less fuel mileage. But at a steady 55-65 MPH (yes, there have been a number of times I went fill-up to fill-up at about 60, and NOT by choice), I have hand calculated 27-28 MPG on the 4.6L. Make that 80-90 MPH pump-to-pump and I average about 18-19 MPG.

slyter485

I've found the onboard mileage calculator to be surprisingly accurate too, within .2mpg calculated. That's pretty good for the passengers and extra weight in the trunk.


+1 on what gears you have.

beerman616

I just did a 3,000 mile trip from South Carolina up to Upper Michigan, down through Wisconsin, and back to South Carolina. Most of the freeway time was a minimum of 75-80 mph, quite a few times over 80, with a couple quick runs over 100. I also may have left a couple black marks in front of my in-laws when we were having a family reunion (common occurrence with the yoopers I know).

I averaged (according to the in-dash measurement) 22 mpg for the entire trip meter. I used the second trip meter to measure each tank, and they ranged from around 17 mpg up to almost 25 mpg. I hand calculated several tanks to see how accurate and it was always within about .3 mpg of the in-dash calculation.

My car is a '13 gt, 6 speed manual, with 3.73's running premium the whole trip. Just the wife and I with a full trunk and backseat.

xtn

Base model with the 3.31 I believe. I'm going to take a look at the diff to confirm though. I'm back to city driving

slyter485

If you still have the dealer window tag (I assume you bought it new), it will say on there if you have anything other than 3.31.

xtn

Yea I checked the diff and it's 3.31. These gears feel so short to me I can't imagine going with anything higher. I guess I'm used to the 5 speeds.

superslow86

Nice. surprising to say the least.

baddog671

I've driven a similar route quite a few times, Western MD to SW FL, 1200 miles. Best tank was 29.4mpg with 425.5 miles. With 3.31's and less weight, I don't see the 30 mark being far fetched.