4.3L EcoTec3. Click to enlarge.

Buyers can choose from three new EcoTec3 engines—a 5.3L available at launch, followed by the 4.3L and 6.2L versions available later this year. All are designed specifically for the high trailering and hauling demands unique to truck buyers.

The new EcoTec3 engines feature three advanced technologies—direct injection, cylinder deactivation and continuously variable valve timing (CVVT)—to make the most of power, torque and efficiency across a broad range of operating conditions.

Sierras equipped with the 4.3L EcoTec3 V-6 will have trailering ratings up to 7,200 pounds (3,266 kg) for a regular cab, short bed, four-wheel-drive model – 500 pounds more than the most capable Ford F-150 3.7L and 700 pounds more than a Ram 1500 3.6L. Sierra’s standard V-6 produces an SAE-certified 285 horsepower (212 kW) and is matched with a proven, efficient six-speed automatic transmission. EPA fuel economy estimates will be released later.

The EcoTec3 engines were optimized through 6 million hours of computational analysis by engineers studying the combustion process. In all, 10 million CPU hours were spent on the EcoTec3 engines.

In 1960, GMC debuted the first V-6 pickup truck ever and offered it exclusively through most of the ’60s. That engine, offered in various displacements starting at 5.0L, was designed with aluminum pistons, improved cooling and a stout crankshaft and bearings.

Like the 2014 engine, the 4.3L V-6 introduced as standard equipment for GMC half-ton pickups in 1985 used geometry and engineering from the brand’s proven Small Block V-8. As with today’s V-6, engineers studied the combustion chamber, developing “Vortec” technology that swirled the air and fuel inside the engine to create a more homogenous mix, improving power and efficiency. That engine was the basis for new generations of engines through the 2013 model year.

2014 Sierra models with the 4.3L EcoTec3 V-6 go on sale later this year with a suggested starting price of $25,085, including a destination charge of $995 but excluding tax, title, license and dealer fees.