GM Drops New Turbo-4 Into Chevy Silverado
The redesigned Silverado will offer a 4-cyl. engine with cylinder deactivation – unimaginable in fullsize pickups not long ago – while V-8s also will benefit from a sophisticated new cylinder-deactivation technology.
MILFORD, MI – General Motors reveals key propulsion elements for its redesigned ’19 Chevrolet Silverado, a technological burst that includes an all-new turbocharged 4-cyl. gasoline engine and an advanced fuel-saving cylinder-deactivation system for the fullsize truck’s proven V-8s.
“We asked what would work best for this truck, focusing on less noise and vibration and less mass,” says Tom Sutter, chief engineer on the 2.7L inline-four.
The answer was a 4-cyl. with a V-6-like 310 hp plus a whopping 348 lb.-ft. (472 Nm) of torque. The torque figure is 22% greater than the current Silverado base engine, a 4.3L naturally aspirated V-6. It reaches 90% of peak torque at 1,500 rpm, which GM considers best in the segment, and hits that mark in 1.9 seconds.
The 4-banger is 100 lbs. (45.3 kg) lighter than a V-6 of comparable performance and pushes the Silverado to 60 mph (97 km/h) in less than seven seconds. It is a clean-sheet design three years in the making and specific, for now, to the Silverado.
“It was designed from the ground up as a truck engine,” Sutter says during a briefing at the GM Proving Grounds here on the Silverado propulsion strategy.
Technical highlights for the 4-cyl. include an industry-first three-mode valve train to balance efficiency and power. High valve lift delivers full power, low valve lift provides cruising efficiency and zero valve lift occurs during cylinder deactivation, which will be applied to two of the four cylinders during light load.
A dual-volute turbocharger with electronic boost control sourced from BorgWarner uniquely sends high-pressure exhaust gas through opposite sides of the turbocharger housing to spin the turbine. The result in the 4-cyl. is higher pressure, greater flow and cooler exhaust that requires less aftertreatment.
Active thermal management uses targeted engine heating and cooling to improve engine performance in hot and cold ambient temperatures.
An integrated exhaust manifold within the head of the 4-cyl. recovers exhaust heat for faster engine and transmission warmup, with quicker turbo response, GM says.
The engine also receives an electric water pump instead of an engine-driven pump to enhance efficiency and ensure stable cabin temperatures when the stop/start system shuts off the engine.
The 4-cyl. engine employs a variable-pressure oil pump, gasoline direct injection and dual overhead cams. It is mated to an 8-speed automatic transmission.
GM says EPA-rated fuel economy numbers will come later, as well as towing and payload capacities. The engine is built at GM’s Spring Hill, TN, engine plant.
The V-6 will remain in the Silverado propulsion portfolio for 2019. The 4-cyl. becomes the base engine in the Silverado LT and first-ever Silverado RST. The 5.3L and 6.2L V-8s keep their position as the top dogs in the lineup.
The V-8s will employ an advanced cylinder-deactivation technology called Dynamic Fuel Management. DFM allows the engines to operate in 17 different patterns to optimize power and fuel efficiency.
They previously used GM’s Active Fuel Management system, which operates the engines in either 4- or 6-cyl. modes.
GM says during a recent industry-standard test cycle, a ’19 Silverado 2-wheel-drive with a 5.3L V-8 and DFM operated with fewer than eight cylinders more than 60% of the time, which is 9% more than a comparably equipped ’18 model with AFM.
Analysis work for the application of DFM was equivalent to an all-new engine, says Jordan Lee, chief engineer for GM small-block V-8s. GM vehicles with cylinder deactivation date back to 2005.
The redesigned Silverado goes on sale in the third quarter with the V-8s, followed in the fourth quarter with the 4.3L V-6 and new 2.7L turbo 4-cyl.