Recenlty I got a new job which requires a greater commuting distance. I have seen the tuners out there(Diablo trinity and SCT) that offer tunes from perfomance gains but I was wondering if you can also tune to improve the gas mileage for long commutes. I have an 09 GT with stock performance.

 

yes, most of those tunes do help MPG.

With just a mere tuning of your Air fuel ratio will give you better more efficent use of your gas. There are more parameters than that obviously but the whole reason those work to get more hp is because its using everything more effiencently, hp and mileage go hand in hand in a tuning aproach.

 

For normal ( not spirited ) driving, you will probably see an MPG increase with a custom tune. Even though my Mustang is supercharged, I see a 2 MPG increase during normal driving, with a JDM Engineering custom tune.

 

Same here. With just a tune I got better milage. Now, even supercharged with 4.10 gears and auto trans I get 15mpg in town, only 22 Hwy (that's the gears).
CAI & tune will improve mpg if you regulate your right foot pressure well. I have to admitt I'm not the best at that.
"Smiles per gallon, PRICELESS!!!"

 

What mileage are you getting now smitty?

 

I got around that as well, I don't even bother looking when the supercharger really gets cooking.

 

the tune will help some, but the driving habits will help more. Short shifting, tire pressure correct (or a little above), 65-70 instead of 80 mph, make sure the trunk is cleaned, take out the subs if you have them and spare if you have the courage and carry fix a flat instead.

 

could some of you guys post your actual mileage- I'd love to be better able to justify a tuner

my stock 06 gt stick w/3.55s averages 18 on my daily commute (mostly 35-45 zones/start/stop) on 87 octane, I get 20 with 89, but idle/lowend is not as good on 89, as its not tuned for it. highway at 65 I got 24 on the one long road trip to date...

I KNOW it can do better, as the wifes 07 (2wd-5.3 V8) avalanche got almost 23 on a 4000 mile road trip...that things gotta weigh at least half a ton more+ had 6 people and luggage- and several hundred pounds of decorative stone from a shop in colorado

I had a 85 camaro(sorry) that got 24 like a clock on the highway, but one long trip out west got 35 (both ways) at 80~85 going across the desert...
kinda curious as to what rpm/mph is most efficient for the mustang...but to date would have to suspect about 24mpg at 60mph is it for mine.

really curious as to whats the best highway mpg(and at what mph) that can be had with 331/355/373/410 gearsets and a good tune...would love to hear of 27-28 at 65 with 3.55 gears, but think that could be a bit of a stretch