In the wake of the ongoing revelations about Volkswagen (VW) deliberately manipulating powertrain control software in order to pass emissions tests in Europe and the United States, it would have been unsurprising if General Motors (GM) and other automakers immediately cancelled all future diesel engine plans. Instead, GM remains fully committed to a broad portfolio of fuel efficiency technologies that include diesel engines in a variety of vehicles.
In June 2015, Dan Nicholson, GM vice president of global powertrain development, announced that “GM wants to be considered the leader in North American passenger car diesels.” The same month, Nicholson also spoke to the media and to analysts at a Chevrolet technology forum where the second-generation Cruze was revealed. In North America, the new Cruze will be offered with two four-cylinder powertrain options, a 1.4-liter turbocharged gasoline engine, and a 1.6-liter diesel.
Diesel on Schedule
Barely 2 months later, the automobile leader that Nicholson wanted to dethrone began imploding from self-inflicted wounds and proceeded to take an entire class of fuel-savings technology down with it. Despite the acknowledged illegal actions of VW and unconfirmed reports that other manufacturers may have cheated in a similar fashion, Mark Reuss, GM executive vice president for global product development, is staying the course.
Reuss told a group of North American Car and Truck of the Year jurors in early November that the next-generation Cruze diesel remains on schedule for production in 2016. That announcement came as GM revealed that the diesel-powered 2016 Chevrolet Colorado and GMC Canyon had officially been certified by the U.S. Environmental Protection Agency (EPA) as the most fuel efficient pickups in the United States with an estimated 22 mpg city, 25 mpg combined, and 31 mpg on the highway.
The certification of the new trucks was due right around the time that the VW scandal went public and was held up for several weeks as the EPA decided that these should be among the first vehicles to undergo additional road testing in order to validate the results of the usual lab tests.
Unlike VW’s four-cylinder diesel engines, the GM trucks and the Cruze utilize a urea-injection system to control emissions of nitrogen oxides (NOx). During development prior to the launch of the Cruze diesel in 2013, Chevrolet did test the same lean NOx trap technology used by VW, but found it inadequate to meet EPA and California Air Resources Board standards.
During a weeklong evaluation earlier this year, a 2015 Cruze diesel returned 39 mpg in combined driving with the older 2.0-liter engine that was then in use. The 2017 Cruze diesel will be powered by a new 1.6-liter engine that debuted earlier this year in several Opel models in Europe. In the Cruze, the new engine is expected to easily beat the 33 mpg combined rating of the old model.
Navigant Research’s Automotive Fuel Efficiency Technologies report projects that diesels will only account for about 3% of North American light duty vehicles sales in 2025, but GM wants a big piece of that market as the company takes advantage of every technology in its portfolio. GM is already aggressively slimming the mass of its new vehicles and adding automatic stop-start as a standard feature on many models. In the next year, the company is set to launch new conventional and plug-in hybrid electric systems, the 200-mile Bolt electric vehicle, and by 2020 plans to launch fuel cell electric vehicles. No stone—including diesel—will be left unturned by GM.