The updates will likely be applied with the upcoming Chevy Silverado HD and GMC Sierra HD model refresh / mid-cycle enhancement, currently expected to arrive for the 2023 model year. However, it should be noted that there are rumors that Chevy Silverado HD and GMC Sierra HD model refresh could be pushed back to the 2024 model year.
When equipped with the 6.6L V8 L8T gasoline engine, the current Chevy Silverado HD and GMC Sierra HD are rated at 401 horsepower at 5,200 rpm and 464 pound-feet of torque at 4,000 rpm. When equipped with the 6.6L V8 L5P turbodiesel Duramax, output is rated at 445 horsepower at 2,800 rpm and 910 pound-feet of torque at 1,600 rpm. The gasoline engine mates to a six-speed automatic transmission, while the diesel engine mates to a 10-speed automatic transmission.
For reference, we’ve included a list of the four heavy-duty trucks currently on the market, including both GM trucks and their rivals, as well as their respective powertrains and output figures:
|Vehicle||Engine||Fuel Type||Aspiration||Valvetrain||Horsepower (hp @ rpm)||Torque (lb-ft @ rpm)|
|2021 Chevy Silverado HD||6.6L L8T V8||Gasoline||Atmospheric||OHV 16-valve||401 @ 5,200||464 @ 4,000|
|2021 Chevy Silverado HD||6.6L Duramax L5P V8||Diesel||Turbocharged||OHV 32-valve||445 @ 2,800||910 @ 1,600|
|2021 Ford Super Duty||6.2L Boss V8||Gasoline||Atmospheric||SOHC 16-valve||385 @ 5,750||430 @ 3,800|
|2021 Ford Super Duty||7.3L Godzilla V8||Gasoline||Atmospheric||OHV 16-valve||430 @ 5,500||475 @ 4,000|
|2021 Ford Super Duty||6.7L Power Stroke Scorpion V8||Diesel||Turbocharged||DOHC 32-valve||475 @ 2,800||1,050 @ 1,600|
|2021 GMC Sierra HD||6.6L L8T V8||Gasoline||Atmospheric||OHV 16-valve||401 @ 5,200||464 @ 4,000|
|2021 GMC Sierra HD||6.6L Duramax L5P V8||Diesel||Turbocharged||OHV 32-valve||445 @ 2,800||910 @ 1,600|
|2021 Ram HD||6.4L HEMI V8||Gasoline||Atmospheric||OHV 16-valve||410 @ 5,600||429 @ 4,000|
|2021 Ram HD||6.7L Cummins I6||Diesel||Turbocharged||OHV 24-valve||370 @ 2,800||850 @ 1,700|
|2021 Ram HD||6.7L Cummins I6 HO||Diesel||Turbocharged||OHV 24-valve||420 @ 2,800||1,075 @ 1,800|
It’s also worth mentioning that Ford is rumored to be working on a twin-turbo version of its 7.3L V8 Godzilla gasoline engine. Make sure to check out the full story from our sister publication, Ford Authority.
The refreshed Chevy Silverado HD and GMC Sierra HD will follow model refreshes / mid-cycle enhancements for the Light Duty Chevy Silverado 1500 and GMC Sierra 1500, slated to debut with the upcoming 2022 model year.