Emissions Yesterday, Today and Tomorrow: One Test or Two?
(Article credit to TruckinInfo.com, author Rolf Lockwood)
Phase 2 of the fuel-efficiency/greenhouse gas regulations will soon be unveiled, demanding even tougher, more stringent CO2 and fuel-consumption reductions of medium- and heavy-duty trucks.
Engines and vehicles are tested separately in Phase 1, but there are those who urge that just one test, with engines rolled into the whole truck like any other component, is the better approach.
As things stand now, engines are tested on a dynamometer as they have been all along, and Cummins thinks it should stay that way, according to Brian Mormino, executive director, worldwide environmental strategy and compliance at Cummins.
Among other reasons, Mormino told us in a lengthy interview, this would preserve spec’ing flexibility for truck buyers and ensure repeatability in the testing process.
Trucks, on the other hand, are tested by way of computer modelling in Phase 1, with some inputs coming from on-track trials using standard SAE protocols and that data then fed into the modelling software. Daimler and Volvo (including Mack), the only fully integrated OEMs, are arguing that a single all-inclusive test would be simpler and more cost-effective.
Mormino says the implementation of Phase 1 was pretty much seamless, and he attributes that success largely to the continued use of familiar regulatory tools and testing methods that had been in place for decades. For 30 years engine makers have tested NOx and particulates on the dyno, and it was easy to include CO2 as well.
“We just added CO2,” Mormino says, “which means that we allowed all that diversity to continue in the marketplace because the engine is certified to operate in a wide range of vehicles and applications. So customers and end-users still have all the choice that is really, really important… in terms of all of their preferences and the types of work they have to do. The regulation didn’t… limit their choices.”
Perhaps a more compelling argument is the one he makes about the huge number of fuel-economy variables when a truck is put to use. Like driver skills, terrain, trailer type, highway or city, load, and countless others.