2016 GMC Sierra eAssist Second, Simpler Approach to Hybrid Truck
System to be Test-Marketed in California
Not that anyone noticed the first time, but there’s already been a fullsize hybrid pickup. General Motors developed an advanced two-mode hybrid system for its fullsize trucks and SUVs that sold between 2009 and 2012. While the system worked reasonably well and delivered a measurable improvement in fuel economy, the complexity and cost of the system, as well as the significant reduction in towing capacity compared to its non-hybrid counterpart, sunk the system from the start. While the two-mode system delivered a 5 mpg improvement in EPA city fuel economy, its 2 mpg improvement in highway fuel economy did little to pique truck buyers’ interest. GM hasn’t totally given up on the idea of a hybrid pickup. However, this time around, the hardware is much simpler, and the benefits arguably more tangible.
Whereas the two-mode hybrid system added a substantial 450 pounds to the Sierra and Silverado models, the new eAssist system adds only about 100 pounds and consists primarily of a small 0.45 kWh battery between the front seats, which powers a compact induction motor mounted on the accessory drive that enables auto stop-start capability and regenerative braking. If this sounds familiar, it’s the same concept as the belt-alternator-starter (BAS) hybrid system that was used on the previous-generation Chevy Malibu hybrid and other GM passenger cars. Naturally, the system’s main appeal is improved fuel economy, and the system is expected to yield a 2 mpg improvement in city and highway fuel economy over an equivalent 2WD Sierra 5.3L with the eight-speed automatic, for 18 mpg city, 24 mpg highway, and a 20 mpg combined rating.
A soft tonneau cover and active grille shutters also incrementally improve efficiency. GM claims the system can add up to 13 hp and 44 lb-ft of boost under high-load conditions. A significant difference over the last two-mode hybrid system is a substantial and competitive 9,400 pound towing capacity. The two-mode hybrid trucks had a towing capacity of between 6,100 pounds for 2WD models and 5,900 pounds for 4WD models.
Unlike the last-generation Sierra Hybrid, which was offered in two- or four-wheel drive, the eAssist system will initially be offered only on 2WD models and only on SLT Crew Cab models with the Premium Plus package. The truck will be test-marketed starting spring 2016 in California, with only 200 units made available for the model year. GMC says it will monitor consumer response to the model in consideration of a possible nationwide offering in 2017.