GMC Duramax Diesel 2015 Owner's Manual page 81

10-2 Vehicle Care
Aftermarket Engine
Performance Enhancement
Products and Modifications
Some aftermarket engine
performance products and
modifications promise a way to
increase the horsepower and torque
levels of the vehicle's powertrain.
You should be aware that these
products could have harmful effects
on the performance and life of the
engine, exhaust emission system,
transmission, and drivetrain.
The engines, transmissions, and
drivetrains have been designed and
built to offer industry leading
durability and performance in the
most demanding applications.
Engine power enhancement
products may enable the engine to
operate at horsepower and torque
levels that could damage, create
failure, or reduce the life of the
engine, engine emission system,
transmission, and drivetrain.
Damage, failure, or reduced life of
the engine, transmission, emission
system, drivetrain, or other vehicle
components caused by aftermarket
engine performance enhancement
products or modifications might not
be covered under the vehicle
warranty.