The GMC Sierra Heavy Duty hog mollies are back for the 2021 model year—how could you miss them? In comparison to the Chevrolet Silverado HD siblings, the GMC versions are considerably more rock ‘n’ roll. This year’s upgrades include models of the truck that go further off-road (X31) and go above and
With twin rear wheels and a V-8 engine, the F-150 is still available in 2500 and 3500 versions, including single or dual rear wheels and one of two V-8 engines. Regular, double, and crew cab versions are all available; the last of which is more popular with commercial buyers.
Although it is a 9.7 in curb weight, the new Ford F-150 is actually a 7.0 on our scale because of two important asterisks—heavy-duty pickups aren’t rated for fuel economy or safety. If it was given a score, it would almost certainly bring down that number; the vehicle lacks standard active safety features.
2018 2019 2020 2021 GMC Sierra 2500 Engine Oil Capacity
| Engine | Engine Oil Capacity with filter | Oil Type |
| 6.6L 8-cyl Engine L8T | 8 quarts (7.6 liters) | 5W-30, 0W-30 (Below -29) |
| 6.6L 8-cyl Engine L5P Diesel Turbo | 10 quarts (9.5 liters) | 15W-40 (Above -18), 5W-40 |
| 6.0L 8-cyl Engine LC8 Flex | 6 quarts (5.7 liters) | 5W-30, 0W-30 (Below -29) |
| 6.0L 8 -cyl Engine L96 Flex | 6 quarts (5.7 liters) | 5W-30, 0W-30 (Below -29) |
2013 2014 2015 2016 2017 2018 GMC Sierra 2500 Engine Oil Capacity
| Engine | Engine Oil Capacity with filter | Oil Type |
| 6.0L 8-cyl Engine L96 | 6 quarts (5.7 liters) | 5W-30, 0W-30 (Below -29) |
| 6.0L 8-cyl Engine L96 Flex | 6 quarts (5.7 liters) | 5W-30, 0W-30 (Below -29) |
| 6.6L 8-cyl Engine L5P Diesel Turbo | 10 quarts (9.5 liters) | 15W-40 (Above -18), 5W-40 |
| 6.0L 8-cyl Engine LC8 | 6 quarts (5.7 liters) | 5W-30, 0W-30 (Below -29) |
| 6.6L 8-cyl Engine LML Diesel Turbo | 10 quarts (9.5 liters) | 15W-40 (Above -18), 5W-40 |
2007 2008 2009 2010 2011 2012 GMC Sierra 2500 Engine Oil Capacity
| Engine | Engine Oil Capacity with filter | Oil Type |
| 6.0L 8-cyl Engine L96 | 6 quarts (5.7 liters) | 5W-30 |
| 6.0L 8-cyl Engine L96 Flex | 6 quarts (5.7 liters) | 5W-30 |
| 6.6L 8-cyl Engine LML Diesel Turbo | 10 quarts (9.5 liters) | 15W-40 (Above -18), 5W-40 |
| 6.6L 8-cyl Engine LGH Diesel Turbo | 10 quarts (9.5 liters) | 15W-40 (Above -18), 5W-40 |
1998 1999 2000 2001 2002 2003 2004 2005 2006 GMC Sierra 2500 Engine Oil Capacity
| Engine | Engine Oil Capacity with filter | Oil Type |
| 6.0L 8-cyl Engine | 6 quarts (5.7 liters) | 10W-30 (Above -18), 5W-30 |
| 6.6L 8-cyl Engine LB7 Diesel Turbo | 10 quarts (9.5 liters) | 15W-40, 10W-30 (Above -18), 5W-40 |
| 8.1L 8-cyl Engine | 6.4 quarts (6.1 liters) | 10W-30 (Above -18), 5W-30 |
| 5.3L 8-cyl Engine LM7 | 6 quarts (5.7 liters) | 10W-30 (Above -18), 5W-30 |
GMC introduced a new off-road AT4 trim for the Sierra heavy-duty pickup last year, which was significantly updated with a more robust frame, revised powertrains, and a new MultiPro tailgate. The GMC Sierra 2500HD is comparable to the Chevrolet Silverado 2500HD, but it offers features exclusive to GMC models such as the MultiPro tailgate. The GMC Sierra 2500HD competes against other large trucks including the Chevy Silverado 3500HD, Ford F-250 Super Duty, and Ram 2500 Heavy Duty.
The GMC Sierra Denali is a true workhorse that has it all. The truck’s length and heft are equally amazing. GMC does little to hide the vehicle’s mass—it’s fine. A 6.6-liter gas V-8 is standard and produces 401 horsepower. It can haul more than three tons in the bed if required, with help from a 6-speed automatic transmission and better for it. A 6.6-liter turbodiesel is an expensive upgrade, but it comes with eye-catching stats: 445 horsepower, 910 lb-ft (up to 35,500 pounds of towing). It’s mated to a smooth 10-speed automatic and benefits hugely from it.
The most popular configuration is the crew cab, which can accommodate up to five people. GMC offers short- or long-bed configurations on most models (except regular-cab pickups, which only have a long bed), and its deep and wide seat supports a lot. Most trucks come with a hidden tailgate that’s useful—as long as you don’t smash it into a trailer hitch.
The 2021 GMC Sierra Heavy Duty trucks have two V-8 engines that provide tremendous power, but the ride is only so-so. The Sierra Heavy Duty receives another point added to its bruising V-8 engines, which has a starting average score of 5. It’s a 6 in total. GMC offers heavy-duty trucks with two configurations: 2500 and 3500, with the latter available with a dual rear axle system. Rear-wheel drive is standard, and four-wheel drive is frequently installed as an upgrade. Two separate rear axle ratios are accessible depending on need, and the turbodiesel V-8 engine includes an integrated power take-off to power equipment such as tractors.
The base gas engine is a 6.6-liter gas V-8 that generates 401 horsepower and 464 pound-feet of torque. It can haul 7,442 pounds in dual-rear-wheel trim or 4,534 pounds in single-rear-wheels version. A 6 speed automated gearbox transfers power to the gas engine.
