General Motors plans to invest $60 million in its DMAX powertrain JV with Japanese auto maker Isuzu to make design changes to the 6.6L turbocharged diesel V-8 engine produced at the facility, targeting greater efficiency ahead of future U.S. emissions standards.
The 6.6L Duramax turbo diesel V-8, produced at DMAX in Moraine, OH, since 2000, appears in the Chevrolet Silverado and GMC Sierra Heavy Duty pickups, as well as the Chevy Express and GMC Savana large vans.
“Today’s announcement demonstrates GM’s commitment to continuously invest in technologies that reduce the impact of our vehicles on the environment, while maintaining performance attributes required by customers in the areas of towing and hauling loads,” GM North America Manufacturing Manager Christine Sitek says in a statement.
According to GM, the design changes will meet the EPA’s “Tier 3” tailpipe and evaporative emissions standard coming in 2017 for light-, medium- and some heavy-duty vehicles. The federal law mirrors a new standard on the way from California regulators, also due in 2017. Connecticut already has instituted tougher regulations on this front.
The new federal standard was encouraged by automakers, because it allows them to outfit vehicles with the same powertrains and emissions standards in every state.
The rules also will reduce the amount of sulfur refiners put in diesel fuel, clearing the way regulators say for even greater efficiency from diesel exhaust system catalysts already cleaning up more than 90% of tailpipe emissions. Perhaps more importantly, lower-sulfur diesel fuel will lead to less-expensive catalyst technologies and make diesels now selling at a premium to gasoline engines more affordable.
The Duramax diesel currently produced by DMAX generates 397 hp at 3,000 rpm and 765 lb.-ft. (1,037 Nm) of torque at 1,600 rpm. The engine uses high-pressure (30,000 psi/2,000 bar) Piezo injectors to balance efficiency with the performance demands of customers who use the big GM pickups and vans for towing and hauling.
During recent testing of the redesigned ’15 Silverado and Sierra three-quarter-ton pickups in Phoenix, WardsAuto averaged 24.4 mpg (9.6 L/100 km) in a segment of highway driving. Pulling a 10,000-lb. (4,536 kg) trailer, fuel economy sunk to 11-12 mpg (21.4-19.6 L/100 km), an average far above a comparably sized gasoline V-8 engine.
DMAX has built nearly1.6 million engines since it launched production. GM owns 60% of the JV.
Future fuel-economy and emissions standards are driving automakers to diversify their lineups with diesel technology.
GM last year introduced the Chevy Cruze Clean Turbo Diesel, powered by a 2.0L turbodiesel homologated for the U.S. from Europe. The automaker also has had on the shelf for a number of years a Duramax 4.5L V-8 turbodiesel designed for use in its half-ton trucks, SUVs and CUVs and recently signaled it may begin development on it again soon.
Chrysler this week begins selling a version of its Ram 1500 light-duty pickup with a 3.0L turbodiesel engine. Nissan plans a diesel engine for its next Titan pickup.
Today’s announcement from GM comes ahead of additional powertrain news expected from the automaker next month. Sources tell WardsAuto the automaker will reveal a new small engine for global application.
