R U Jimmy Ray

Apples to oranges, but the wifes '10 SS L99 city mileage went up 1 MPG, lost about 2 on the highway (tune). So much smoother, no vibrating belching and surging in-and-out of 4/8.

00pooterSS

iTrader: (40)

Got it tuned a couple of weeks ago and for anyone considering tuning theirs you should drive it off the lot to the tuner. Much better now, and it's mostly due to the trans tuning, having the AFM/DOD turned off is nice too.

I've been beating on it a lot on e85 and having fun, but this week I ran it on 93 and it actually looks like it has picked up 2-4 mpg (too subjective and too soon to really give a closer estimate) but it definitely picked up mpg after the tune. I'll have to try 87 next and see if there's any change.

Before the tune I would regularly get around 14 mpg (per the dash) on a tank. Right now with a lot of wasteful type of driving it's at 17 and my 25 mile mpg tracker is at 18 (I started driving it more "normal" yesterday).


Vortec350SS, that's a good question but I bet everyone is comparing stock to tuned.

JRoyPDX

My comparison was stock, then stock with disabled afm.