“The future is going to be all about reducing emissions of CO2 - shorthand for increasing fuel economy,” Diesel Technology Forum’s Schaeffer says. “One big shift is that instead of just focusing on making the engine more efficient, any future effort is likely to focus on the total vehicle. The truck, its tires and its aerodynamic profile all have significant impacts on fuel economy.”
He points to a substantial research effort on approaches for improving fuel economy in medium and heavy duty vehicles just completed by the National Academy of Sciences. The research, presented to the National Highway Traffic Safety Administration, forecasted about 20 percent more improvement in energy efficiency out of the engine alone. It said the use of hybrid powertrains in medium duty pickup and delivery type vehicles will grow, and efforts to improve aerodynamics in trucks and trailers will take on new significance, as will tires and how the driver drives - a key variable in reducing fuel consumption from heavy duty trucks.
The engine is a piece of the equation and so is aerodynamics, says Navistar’s Shick. “In our testing and research, we’ve found that in round numbers, about 50 percent of the fuel consumed by a highway tractor at 60+ mph is used to overcome aerodynamic drag. Another 15 to 16 percent is the engine itself and the balance is the load - tires against the pavement, geartrain, etc. So a relatively small portion of fuel use is due to the engine.”
For post 2010, efforts will be focusing on an integrated vehicle for more fuel economy and reduced emissions, he says and “we’ll see very different looking configurations aerodynamically for both tractors and trailers, particularly trailers as not much has been done with them.”
DTNA’s Lampert notes that the U.S. Department of Energy’s SuperTruck Program has awarded grants to the truck manufacturing industry to develop the next generation of fuel efficient heavy duty trucks. Project goals include the demonstration of a 50 percent total increase in vehicle freight efficiency through a five-year research and development process focusing on advanced vehicle systems and engine technologies.
DTNA is a recipient of some of the program’s $187 million grant money. So are Cummins, Navistar and Peterbilt.
“It’s hard to imagine cranking down any further on heavy duty diesel emissions standards like NOx and PM, given that they are so close to zero,” says Schaeffer of the Diesel Technology Forum. “I think the emphasis for new vehicles is going to be holding the line on emissions, but seeing targets for reductions in CO2 and gains in fuel efficiency.
“However, I think that if there is any additional regulatory activity on the emissions aspects of diesel, it is more likely to come in the form of addressing emissions of the in-use fleet of vehicles with a focus on fleet operations, more so than new engine technology/standards and manufacturers. The Diesel Emissions Reduction Act established a voluntary incentive-based program aimed at on- and off-road fleets to modernize and upgrade their older technology through a variety of approaches, including repowers - putting in newer engines, adding emission control devices like particulate filters or oxidation catalysts, etc.”
The next regulations come in 2013 when all on-highway diesel engines will require on-board diagnostics (OBD) systems, says Nycz of Cummins.
Manufacturers must install OBD systems that monitor the function of emission control components and alert the vehicle operator to any detected malfunction or deterioration with the emissions system prior to emissions exceeding a threshold. When a malfunction occurs, diagnostic information must be stored in the engine’s computer to assist in diagnosis and repair of the malfunction.