Also helping avoid problems was the leveraging by the manufacturers of their extensive European experience with SCR and EGR emissions technology.
There are no significant changes to maintenance with the 2010 EPA engines, notes Cummins’ Nycz, with primary engine maintenance intervals remaining unchanged. With the exception of changing the diesel exhaust fluid filter, there are no additional changes to maintenance practices or procedures, adds DTNA’s Lampert.
“To see these new engines come out with near zero emissions and be as clean as alternative fuels is nothing short of a major milestone,” says Diesel Technology Forum’s Schaeffer. “The level of research and innovation that the engine and truck makers have done to get here is extraordinary. This accomplishment positions clean diesel as a technology for the future.”
He points out that clean diesel technology involves three pieces. One is low sulfur diesel fuel - is a cleaner-burning diesel fuel that contains 97 percent less sulfur than low-sulfur diesel and allows the use of improved pollution control devices that reduce diesel emissions more effectively. The other two pieces are low-emitting diesel engines and advanced emissions control devices. There is also the element of being able to leverage programmable electronic features, says Nycz of Cummins.
The “most extraordinary fact” is that heavy duty on-highway diesel engines manufacturers have been making dramatic strides in recent years in reducing emissions and at the same time increasing fuel efficiency - basically competing forces in diesel engine design, says McKenna of Mack Trucks. “These have long been competing goals from both a technical and customer group, adds Schaeffer of the Diesel Technology Forum. “It is remarkable that given the 99 percent reduction in PM and NOx emissions that we have not seen a substantial reduction in fuel economy.”
“Clean Diesel is not a contradiction in terms,” McKenna observes. “The amount of soot is completely invisible to the naked eye. The amount of NOx emitted is essentially zero, or as near to zero as 0.2 grams can be. 0.2 grams equals 0.000441 of a pound. Not much at all.
“Couple the near zero exhaust emissions with a goodly 5 percent improved fuel economy and we are ‘green’ in two ways - we’re environmentally friendly, and we put green dollars back into the customers’ pocketbook with the lower fuel consumption savings.”
“2010 diesel engines are at a level now where in the cities with poor air quality, the ambient air going into the engines is dirtier than the emissions coming out,” Navistar’s Shick says. “You’ve got to wonder how much cleaner diesels can be.” He feels the next focus will be on carbon dioxide (CO2) “because no matter how clean you burn diesel fuel, some CO2 will be formed.”
The EPA does not classify carbon dioxide by itself a pollutant, but considers it a hazard to human health as a greenhouse gas which contributes to global warming, says VTNA’s Saxman agrees. He, too, believes “CO2 will probably be the next focus of regulations, but we’re not at a point yet where this has even been defined.”
“In terms of new emissions regulations, we believe it’s not a matter of if, but rather what and when,” says Cummins’ Nycz. “It is reasonable to assume that in the future, there may be a regulation on greenhouse gases, however any details are unknown at this point.”
It would be near impossible to get today’s heavy duty diesel engines any cleaner, adds McKenna of Mack Trucks. “The next target, I’m sure, will be CO2. This will likely entail various technologies to reduce CO2 production, including but not limited to, more restrictive idle controls, shore power for parked sleeper units, electric APUs, low-rolling resistance tires, all types of truck, tractor and trailer aero aids and the like. The current EPA SmartWay-type vehicle provides a basic model for the future.”