I have a 2008 gasonline 5.4 liter supercrew. I already added a magnaflow exhaust and K&N air intake. For those of you that use tuners, can I expect any MPG increase with a gas motor with an aftermarket exhaust and air intake? I asked the shop that installed the exhaust and air intake and they told me probably not. He said the tuners worked much better with diesel motors and don't do much with a gas motor. I don't tow anything (yet) and am really looking just to improve the MPG if I can. I have read several web pages (hypertech, bullydog, etc) and they don't mention the expected MPG improvement for gasoline engines. Further, has anyone experienced mechanical or operational problems from the use of a tuner? Any input from someone with results would be great. Thanks!

 

best advice for the return of money invested-
keep tires aired up -check once a month [keeps rolling resistance down]
avoid jack rabbit starts
keep unnecessary weight out of truck
use gradual acceleration
keep speed on highway under 65
for the money invested-$0,the return will be a better ratio then the mpg gain you will see from a $400+ tuner if mog gains is your main priority

 

Good advice. Thanks. I have about 2,500 miles on the truck already, but I would imagine it is still breaking in. I have reached 19.2 MPG on the interstate at 75 MPH since I have added the exhaust and air intake. I guess I should be happy with that.

 

see what a steady 65 m ph will get ya,also my best mileage come from driving and allowing the tranny to shift in the meat of the power band,[ where peak tq occurs ],2000-3500 rpms-phil

 

I get 15.5mpg @ 85, so yeah, be happy.