DETROIT - GMC announced the new 2011 GMC Sierra heavy-duty pickups have increased towing and payload ratings through ongoing development and testing, making them the most capable and powerful heavy-duty pickups in the segment. The ratings have been increased to 21,700 pounds of towing and 6,635 pounds of payload.

"When developing the Sierra HD our focus has consistently been to deliver customers the most capable heavy-duty trucks in the market, along with premium features and styling that distinguish GMC amongst the competition," said Rick Spina, GM Full-size Truck global vehicle line executive. "Our first set of capability tests confirmed that the team had exceeded the payload and towing targets by a significant margin. Ongoing testing demonstrated a clear opportunity to increase the true capabilities of these trucks."

The GMC Sierra HD engineering team was able to achieve the increase in towing capacity to 21,700 by putting the Sierra HD through a wide variety of tests over various terrains, grades and weather conditions. Extensive design and lab analysis, climatic wind tunnel testing, and actual on-road extreme ride and handling testing methods were all used to confirm stable handling and performance of the powertrain, drivetrain and brake components at maximum gross combined weight rating (GCWR). The GCWR is increased to 29,200 pounds.

To achieve the increased payload capacity, engineers used higher strength steel for the cargo box sills. The team conducted a significant amount of testing where maximum payloads tested the stronger cargo box and rear axle components. The maximum payload rating has been increased to 6,635 pounds.

"We encourage consumers to test drive the Sierra HD against the competition," said Spina. "Based on our test results, we are confident our HDs will prove to be the best choice for real-world towing and hauling needs."  

For the first time ever, GMC will be offering the exclusive Denali line in our heavy-duty pickups with the Sierra Denali 2500 and 3500 HDs. The Denali version is distinguished by its iconic four-bar, chrome grille with round air inlets, along with body-color bumpers, chrome door handles, chrome accents and and 17- (Dually), 18- and 20-inch polished forged aluminum wheels.

The GMC Sierra HD is the segment leader in diesel horsepower and torque (397hp, 765

lb-ft), conventional towing (17,000 lbs.), 5th-wheel towing (21,700 lbs.), payload (6,635 lbs.) and maximum GCWR (29,200 lbs.). Production for the Sierra HD begins next week at Flint Assembly in Flint, MI and customers can expect to start seeing the heavy-duty trucks on dealer lots shortly thereafter.