Need Some Advice

[ccracin]

This isn't a project question, but I know this is the place to come. My Dad and I have been discussing his disappointment in the performance and gas mileage of his 2007 Sierra 4x4 Quad Cab. It has an Aluminum 5.3 with that cylinder shut down crap. I have a 2004 Sierra with a 5.3 and he had a 2005. My 04 will spank his 07. He gets 13-14mpg and I get 16-17mpg with just about the same driving routine. It also shifts really goofy. Sometimes you think it won't pull a hill without stalling and by that time your foot is so far in it, it shifts and screams up in the r's then shifts again. What gives. He has had it back to the garage a couple times and they say "NO PROBLEM". Bull Sh>>>T No Problem. I have been toying with getting a programmer for it. I don't know whether to get a canned unit or go the HP Tuner route. I've tuned tbi before but have not tackled the newer stuff. Any suggestion or experiences? Any help would be greatly appreciated. The truck looks awesome, but is frustrating to drive. Thanks all.