Superchips Dual-Octane Microtuner for 1996-2003 GM/Chevy Trucks & SUV's and H2 Hummer w/4.8, 5.0, 5.3, 5.7, 6.0, 7.4 & 8.1 V8 engines

Dual Octane - select performance programs for either 87 octane or premium gasoline (max performance)

Retunes the engine for maximum power at all throttle positions

CARB/EPA 50-state legal emissions approved

Recalibrate the speedomter for changes in tire size and/or gear ratio

Premium fuel: 8%-10% more horsepower and 10%-13% more torque. Power ranges from 18HP (4.8L) to 37HP (8.1L)

Adjust the ignition timing to take advantage of 91 to 93 octane fuel when in premium fuel mode

Adjust the air fuel ratio

Firms up the shifts on automatics

Shortens the time it takes the automatic transmission to up shift

Most applications: raise the rev limiter and speed limiter