All the details about the new 6.6L gas V8 and the 6.6L diesel V8 with the 10-speed automatic.
The all-new 2020 Chevy Silverado 2500 and 3500 HD specification, features, and trim levels are all out, but we do not stop there. We spoke to as many engineers as we could to get the details about the new powertrains, chassis, and technologies that allow Chevrolet’s newest trucks to tow up to 35,500 lbs. In this video and article we dive deep into the all-new 6.6L gas V8, its updated 6-speed automatic transmission, the tweaked 6.6L turbo-diesel V8, and the all-new 10-speed automatic transmission.
Before we dig in further, here are the top level specs. The 2020 Chevy Silverado HD is rated to tow up 35,500 lbs with a diesel and will haul up to 7,466 lbs of maximum payload with the gas engine.
6.6L Gas V8
The 6.0L Vortec V8 is going away. In its place is the all-new 6.6L “small block” direct-injected V8 with push-rod valve actuation. The rating is 401 hp @ 5,200 rpm and 464 lb-ft of torque @ 4,000 rpm. GM uses its engine block architecture (cast iron block) and builds on top of it with strengthened components. The combustion chamber compression ratio is set at 10.8-to-1, and Chevrolet says the engine is able to produce maximum torque on regular octane fuel.
The gas engine is mated to an updated 6L90 6-speed automatic transmission. This transmission uses the same housing as before, but it adds a newly designed torque converter and additional clutches to handle the extra power and torque.
The new gas-powered trucks will max out at 17,400 lbs of towing capacity.
6.6L Turbo-diesel V8
The L5P-generation 6.6L Duramax diesel V8 returns for 2020, but it also carries a few updates in order to handle the crazy 52% increase in towing capacity from where it was before. It features improved cooling, a new turbo controller module that brings a 14% improvement in exhaust brake performance, and a larger 28-inch cooling fan in the front to aid the radiator.
The 2020 diesel trucks will also have an after-run feature, that will automatically idle the engine for up to 15 minutes in order to cool down the components if the powertrain was working hard.
The other important piece of the equation is the all-new 10-speed Allison automatic transmission. Chevrolet says that GM and Allison worked closely together in order to develop and test the new transmission. The transmission, the new larger axles, 12-inch rear differential ring gear and the 3.42 rear gear ratio all allow for all 910 lb-ft of torque to be sent to the wheels in first gear.