2003 Chevrolet Silverado 2500HD

The HD variant was a heavy-duty light truck. It was a strengthened version of the Silverado/Sierra light-duty, and was available in the 1500HD, 2500HD, and 3500HD models. The 1500HD, introduced in 2000, offered a Vortec 6000 V8 with 300 hp (224 kW) at 5200 rpm and 360 lb⋅ft (488 N⋅m) of torque at 4000 rpm with a Hydra-Matic 4L80E four-speed automatic transmission. The 2500HD also offered the LB7 Duramax V8 with 300 hp (224 kW) at 3100 rpm and 520 lb⋅ft (705 N⋅m) of torque at 1800 rpm, the LLY Duramax V8 with 310 hp (231 kW) at 3000 rpm and 605 lb·ft (820 N·m) at 1600 rpm, and the LBZ Duramax V8 with 360 hp (268 kW) at 3200 rpm and 650 lb·ft (881 N·m) at 1600 rpm. Also available was the Vortec 8100 V8 with 340 hp (254 kW) at 4200 rpm and 455 lb⋅ft (617 N⋅m) of torque at 3200 rpm.

The 2500HD had an available five-speed (six-speed for 2006-2007 models) Allison 1000 transmission with the Vortec 8100 and Duramax 6.6. The Silverado 3500 offered the same engine/transmission features that the 2500HD, however it was usually equipped with "dually" twin wheels at the rear and had a stronger suspension. The HD models were primarily used for towing and high-weight cargo. The Chevrolet Silverado 2500HD came in at #2 in a 2016 study by iSeeCars.com ranking the top 10 longest-lasting vehicles. The Silverado 2500HD had 5.7% of vehicles over 200,000 miles, according to the iSeeCars study.:)

For 2002, GMC introduced a new limited edition Sierra Professional. Built as either a 1500 or 2500HD Extended Cab Standard Box model with two and four-wheel-drive, the Professional was the ultimate contractors truck. The center console area provided an area to store PDAs, cell phones and laptop computers as well as extra charging points for them and an area to hang file folders. There were also extra storage trays and larger cupholders throughout the cab, including one temperature controlled cupholder. The exterior featured lower body cladding, Professional badging, and a full-chrome grille. These trucks also featured a standard bedliner, box-rail protectors, in-bed power outlet, and many optional accessories suited to tradesmen (ladder racks, toolboxes, etc.). The 1500 series came standard with the 5.3L Vortec 5300 V8, but the 4.8L V8 could be ordered with an option credit if so desired. 2500HD models came with the 6.0L Vortec 6000 V8 only. All trucks had the four-speed automatic transmission with tow/haul mode. Customers could choose from either SLE or SLT decor. The base price for a 2002 1500 2WD with SLE decor was $29,591. 2003 was the final year the Professional was offered.

Towing capacity for the 1500HD is rated at 10,300 pounds (4,700 kg) and can haul 3,129 pounds (1,419 kg) in the bed depending on options. Towing capacity for the 2500HD is rated at 16,100 pounds (7,300 kg) with the gasoline 8.1L V8 with 3.73:1 rear and can haul 3,964 pounds (1,798 kg) in the bed depending on options. Towing capacity for the 3500HD is rated at 16,700 pounds (7,600 kg) and can haul 5,753 pounds (2,610 kg) in the bed depending on options. The addition of 4 wheel drive tends to reduce the towing and carrying capacity by 200 to 400 lb (181 kg), depending upon year and model. Other factors, such as options, can also affect these numbers.