Models equipped with 4.3-liter, 4.8-liter and 5.3-liter engines are matched to a 4-speed automatic transmission. The 6.0-liter and Duramax diesel get a 6-speed automatic. An all-wheel-drive system is available for 1500 models equipped with the 5.3-liter engine.

The Duramax turbo V-8 diesel (260/525) features a selective catalytic reduction system for compliance with federal emissions standards. The system features a 5.8-gallon tank for the diesel exhaust fluid required of SCR systems, and must be refilled about every 5,000 miles, GM said. Electrically heated lines feed the DEF to the emission system to help with cold weather operation.

The Duramax also includes GM’s second-generation diesel particulate filter system, which can go up to 700 miles between regeneration cleanings because of a downstream injection of diesel fuel directly into the exhaust stream. That distance is 300 miles farther than the previous system could go between regenerations, GM said. The downstream injection also helps address concerns about diesel fuel contaminating engine oil when fuel used for regeneration is injected into the cylinder, GM said. A fuel-operated heater that can speed heat to the interior also is available on diesel models, GM said.