New here - had my H2 for 3 years now. Been very happy with it so far.

But I live in Denver part time, and Breckenridge part time. That translates to one round trip up and down the mountains per week.

Overall, I'm very happy with my Hummer, but when going up the mountain at 65 mph, sometimes it has to downshift to very high rpm (read very low gas mileage) to keep up. It would be great to find a little more power.

I've done a bit of reading on the cold air intakes, but am a little skeptical as to whether one would really make that much of a difference by itself. But I'm very willing to go this route because it seems to be pretty cost effective, and if I can get another 1.5 mpg, that would translate to over $400 per year in fuel savings (I drive 25,000 miles per year). Would pay for itself.

I've done some reading on the exhaust mods, too. (i.e. the Corsa). I'm pretty confident that this would give a tangible power increase, but what about fuel efficiency? Anyone with direct experience who can comment would be great to hear from you. Problem with the exhaust mods is cost and noise. Cost could be OK if there is really a fuel efficiency gain. But noise may be a deal killer. This is my every day family vehicle, and I really don't need for it to sound like a hot rod.

Any opinions/comments?

Thanks,
Phil

 

Never seen any gas mileage increases on any of the vehicles I've had with FIPK's, catbacks, and headers on .. a few extra ponies yes ,, increased gas mileage!? More like the opposite .. Then again, more power = more gas ..

 

I did not see any gains in mileage with a exhaust and cold ait intake. If noise is a concern, you can pretty much ditch the catback idea.

 

I have an H3 with a KN CAI and I have noticed about 1-2 mpg difference. The biggest thing I notice is fewer downshifts which keeps the RPM's down. But you will find that you like the performance so your mileage may go down. Depends on your driving habits. Gonna install a Magnaflow cat back system this week, it should free up some more ponies and maybe 1-2 more mpg. If not it was worth it just for the look.

 

I've got the Volant CAI and Magnaflow exhaust. Extra ponies, yeah definately, MPG increase, not a chance!!

Might be the way I drive it though? Drive it like ya stole it!!!

 

the thing is that both CAI and exhausts add power. More power (read: not FI) = lower RPMs. Lower RPMs = less fuel consumption. the only problem is that people like the extra power and want to use it, so they drive faster/take off faster. so if you think you can drive the same way you did before you will notice a difference. now if you want an exhaust thats now loud, consider a muffler swap. Say swap out the current muffler for a flowmaster 70 or whatever you like. that should have a nice rumble under acceleration, but remain relatively quiet under cruising speeds. hope that helps ya out.