Although alternative power is a hot topic in the transportation industry these days, diesel engines still have much to contribute to the clean and efficient energy future, according to Andreas Hoyler, manager engine lab and emissions, diesel systems in North America for Robert Bosch, LLC. Fleet Owner recently had the opportunity to talk with Hoyler about the role the company sees for diesel power today and going forward.
“Diesel power is the most efficient choice available today from a vehicle perspective,” Hoyler said. “The question now is what further potential do we have with diesel if we add other technologies? The goal is to create and promote the most efficient and clean internal combustion system possible.”
According to Hoyler, there is still tremendous upside potential for diesel. In the medium-term, the company sees a vehicle-related potential for saving fuel by perhaps as much as nine percent, he noted, while reducing carbon dioxide emissions from commercial vehicles by “at least twenty percent.” Saving of this magnitude will require improvements in combustion and increases in injection pressures as well as improvements in vehicle aerodynamics and the rolling resistance of tires, he said, along with new technologies like start-stop systems for commercial vehicles.
“Depending upon your operating mode, various power solutions make more sense,” he noted. "In the city [where there is a lot of stop-and-go driving], diesel-electric or diesel-hydraulic hybrids can be a viable choice. Going cross-country, a hybrid does not give you much benefit, but a heat recovery system—adding a little steam engine—to the truck does. Each of these options takes loads off the main engine. The overall goal is fuel efficiency and conserving natural resources.
“Look around,” Hoyler added. “All kinds of power alternatives can make sense, can make a contribution. We see really significant diversity ahead when it comes to vehicle power. Diversity is really the key.
“Of course, you also have to listen to what the market requires in the way of performance,” he observed. “You have to get acceptance from the end user. At the end of the day, you really can’t sell a compromise solution.”
Hoyler also sang the praises of the diesel engine for its flexibility and durability. “Even if we ran out of diesel fuel entirely, we could still run diesel engines on biofuels or convert them to run on natural gas,” he noted.