Does the PCM void the warranty. for that matter does a CAI or exhaust?
sorry if these are "noob" questions

 

GM has a disclaimer in place that says anything that adds horsepower or torque will void your drivetrain warranty. With that said, very few Service Managers will hold you to that with a CAI and exhaust change...but technically they can. I had a talk with my salesman and Service Manager about those mods when I bought the H3 so I shouldn't have a problem. They even told me they would install them, which adds a bit of confidence.

 

I have an '07 that when it is driven on the highway at speeds between 60 and 65mph the mileage I get is 21mpg. Anything over 65 and the mileage plummets. Overall between highway and city driving the vehicle averages about 19. Hope this helps

 

I don't want go this route again with you again Bob...but I believe this to be total BS and I hope you stop putting that out there..I have not seen it, nor does my service manager here in OKC or Little Rock ever seen such a disclaimer...In any event, the Magnuson Moss Act will dispel that disclaimer anyway...Every dealer here in the SW that I know of, are doing aftermarket or OEM mods for performance enhancement to the H3s...I know personally the PCM tuning as is being done by Lund Cadillac/Hummer of Phoenix.. and Albuquerque's Hummer Dealer.

So to answer your question Vince..NO!...you will not void any warranty with a PCM tune, or a CAI, or Cat-back exhaust..So go forth and improve your H3's performance without worry...I'd be more concerned about lift kits that put a stretch on the CV joints.

 

On a 1500 mile trip to Savannah GA the best I could do was 16mpg. That did include mountain driving and often at 80 mph.

 

i got 16.9 on our trip to KY last month
riding at 75 and 80 most of the way
w/ the 33 in tires
i would say the pcm tune helped the mpg because thats the mpg i was gettinw/ the stock tires

 

@ Dennis: Thanks for the info, i appreciate it. I come from fast cars so even though this looks better, its hard to get used to lol.
btw, this is lame i know but i cant find the quote button on this forum. sorry about that

 

Maybe this will help



[IMG]local://upfiles/2455/EE279D406DD74D0CAD97D5DBAE5F212F.jpg[/IMG]

 

Mine is an '07 that currently has about 800 miles on it. First tank about 12.5, next tank just under 14, the next I got over 16 (lots of highway) and just did it again and back to around 12. Mine seems to really like the highway alot better. I do agree with the others, though...the mileage on almost all cars improves significantly after 3-4000 miles. Good luck with it!

 

My tank was topped off and my factory tires were at 44 instead of the recommended 30 psi.
That the only thingI did different. Mine is an 07, purchased in October of 06 with the 3.7 if that makes a difference.