The Chevy Silverado HD and GMC Sierra HD received a complete overhaul for the 2020 model year, with updates applied to the exterior styling, interior, underlying platform, and features list. As it just so happens, the latest T1-based generation of 3500 HD Chassis Cab vehicles also offer three fuel tank options, just like the previous K2-based generation.
More specifically, the latest T1-generation (2020 and 2021 model years) for the Chevy Silverado HD Chassis Cab (3500) and GMC Sierra HD Chassis Cab (3500) come standard with dual fuel tanks, one of which is mounted in front and has a capacity of 23.5 gallons, and the other of which is mounted in the rear between the frame side rails behind the rear axle and has a capacity of of 40 gallons, bringing total available fuel capacity up to 63.5 gallons.
As was the case with the previous K2-based generation, customers considering the new 2020 and 2021 Chevy Silverado HD Chassis Cab and GMC Sierra HD Chassis Cab can choose both tanks as standard, or alternatively, either just the front tank (23.5-gallon capacity) or just the rear tank (40-gallon capacity), making for three fuel tank options total.
For those buyers interested in only the rear 40-gallon fuel tank, the 6.6L V8 L5P turbodiesel Duramax engine is required. The rear fuel tank is also required for the Diesel Exhaust Fluid (DEF) tank relocation, which moves the DEF tank to inside the frame rails, and comes with a DEF tank relocation mounting kit.
To note, the optional 6.6L V8 L5P turbodiesel engine produces 445 horsepower and 910 pound-feet of torque and mates to an Allison 10-speed automatic transmission. Standard spec includes the naturally aspirated 6.6L V8 L8T gas engine, which connects to the MYD six-speed automatic transmission and makes 401 horsepower and 464 pound-feet of torque.