Reviewed By RICHARD J (Parachute, CO) Reviewed for a 2005 GMC Savana —7/13/2014 9:25 PM
Big difference in power. I get 3 to 4 mpg more when using performance level.
Reviewed By Bill H (Ponchatoula, LA) Reviewed for a 2011 GMC Sierra —5/13/2016 6:27 AM
So far I like the performance but really didn't get a fuel mileage increase and also needs some better instructions on how to adjust all the settings. For example how to adjust shift points for certain program's