GMC has found another way to distinguish itself from Chevrolet. It has added an Off-Road Performance Package to the list of available equipment on the Sierra AT4. The upgrade brings along a cat-back exhaust, a performance air intake, and upgraded 6.2-liter engine.
When equipped with the new package, the 2019 GMC Sierra AT4 gets a 10-speed automatic transmission and 6.2-liter V-8 engine that makes 435 hp and 469 lb-ft of torque. That’s up 15 hp and 9 lb-ft of torque from the regular 6.2-liter V-8 available as an option on the Sierra AT4. We tested a Sierra AT4 with this engine, and it was able to hit 60 mph in just 5.8 seconds.
In addition to a beefier engine, the package includes 18-inch machined aluminum wheels wrapped with Goodyear Wrangler DuraTrac tires. Like all Sierra AT4 models, the model comes standard with a two-inch factory suspension lift, two-speed transfer case, a locking rear differential, skid plates, hill descent control, a traction select system, and off-road-tuned Rancho monotube shock absorbers. Optional features include a reconfigurable tailgate, head-up display, rear camera mirror, and late-available carbon fiber composite box.