I see several older post but was wanting some recent info
I looking for a cold air intake. Online did not see the traditional type for the V8.
Also going to install a new exhaust system. I have a very good muffler shop that can do work. Will get them to check my catalytic converters. I see that there are several different mufflers. Would like a little more rumble but not real loud. Finally a tuner that will adjust for the 35s so speedometer and odometer will be correct. I just want a little more throttle response and better mpg
2009 H3T Aplha 120000 miles

 

AirDoc CAI, Tune from PCM of NC. Lots of posts on both.

 

X2, not really going to get better MPG. But you will get better performance.

 

 

Definitely PCM of NC tune, that made the biggest difference for my truck. I have the GM Performance exhaust and Airdoc intake and those didn't make much of a performance increase. The tune removes a lot of the GM torque management which will make a huge difference with your throttle response. I had the 2nd gear shift tightened up too which was nice.

 

I own a 3.7L, but wanted to offer this info. Have had K&N CAI for few years, removed resonator and had cheap AutoZone type pipe running to TB .
Decided to replace that pipe with the Airdoc recently because it's a better quality but also because it has a true 3.5" inside diameter. Took about a week or so for it to settle in with PCM, but I see a big difference from the 3" pipe .
Take same commute since I bought H3 and noticed I'm doing about 82-84mph at 2400 rpm now when I was always about 71-73mph at that same rpm. ( same stretch of highway everyday) its become a routine for me, I find that sweet spot on tach and just drive. I feel a much better response too on the entrance ramp & from a dead stop .
I put this off for a while and regret waiting this long to do it . That cheap $40-$50 stuff was restricting some volume it seems and it made a difference.
Now that's on the I5, so I imagine you would see better results. I may be wrong...not sure.
The PCM tune is plus as well, but they ask about intake before doing it . May want to research the Airdoc. Good luck