You haven't already installed it yet??!?!?!?!

 

Install it only if you want a more aggressive throttle response, much firmer shifts and far better off line, mid and high acceleration for your trip.

 

Not yet but I will soon

 

That's what I wanted it for

 

I installed my tuner

 

I installed the performance tune and went from 26mpg to 14 mpg. Is there a break in or learning period for the tune? It reset my steering mode to standard so I had to change it to sport

 

Hmm, might have something to do with foot, I've read most pick up a couple mpgs with a tune. Hard to believe a v6 can manage that low, my non-tuned 5.0 gets close to 26-27 highway with 3.73s.

 

I was city driving wasn't going more then 30 mph. Does the tuner calculate mpg in real time? My mpg while driving was going between 14 - 16. I just want to make sure everything is how it should be because I have a trip to go on soon

 

cruising at 30mph should be in the 20's for sure - are you saying cruising mpg is 14-16 or average for city driving? Average city should be 14-18 for a GT depending on your driving style

I recently hit 24mpg (confirmed through fill up, not per trip computer) on a pure highway drive with cruise control set at 72mph. Hit about 22 cruising back home at 78-80mph. Average is 20 with mixed back road and highway driving on my ~15 mile commute to work when I do take the car in