We have seen remarkable horsepower and fuel mileage gains by using the HP Tuner Performance Software. There are alot of these guys out there using HP Tuner for GM applications. We are helping them develop performance software for Ford applications. It is a bit pricey, but if you want access to the performance tables and get more power, HP Tuner is a great program for GM vehicles. They even have new protocols for the the New Chevy Camaro and Vette. We have worked with their equipment for a year now, and still learning about all of their applications. We are not paid by HP Tuner. We have done some research with them so we know what their programming can do. Another program for use of computer tuning/ecu tuning is EFI Live, another GM endorsed programing network. Both require labtops with xp, not vista, and warning to anyone using these kinds of programs: 1) save everything you do including stock tables incase you have to restore ecm back to stock, and 2) really should not touch these tables unless you have had a little experince with other computer tuning. It will help you to learn all of the hard ware tuning you can that will help you understand computer tuning.