Not sure which 2003 Hummer H2 Power Programmers & Performance Tuners are right for you? We have over 5642 customer reviews, with an average rating of 4.5, to help you find exactly what you're looking for. Here's what some of our customers have said:
"This product was easy to use and has improved the shift points and horse power of my 2003 H2 HUMMER without any loss in MPG. I actually think it is saving me a few MPG on the 87 octane tune setting versus the factory setting. Non the less, it takes off faster and is less of a brick now without any adverse effects. That is a huge plus for a daily driven rig. I have more options to try for sure, but am so happy with the noticeable difference at the moment. Like butter on ice for now vs. before!" —Jeffrey P from Mission Viejo, CA bought a Superchips VIVID Performance Tuner for a 2003 Hummer H2, 6.0L V8.
"Awesome piece of equipment but not for the novice. This tuner has the ability to fine tune almost every aspect of your vehicle. Without knowledge of the items it can tune for you I suggest: either use the installed program or download a proven program, or change it 1 increment at a time and thoroughly test the tune before adjusting again, just to avoid costly damage no covered by any warranty. Monitor the settings with the unit and create a log file and keep it for reference. With oversize tires, cold air induction, and cat back exhaust and predator i am able to improve my gas mileage by over 4.4 mpg with in town driving. And performance thru the roof :-))
AUTOANYTHING was GREAT TOO!" —Randy L from Orlando, FL bought a DiabloSport PC Interface - USB Cable Kit for a 2003 Hummer H2.