One Test or Two?

A large, 3-part story at the trucking industry news site discusses the history, present and future of emissions testing, and the fuel-efficiency/greenhouse gas regulations, which is in the middle of a tougher, more stringent set of regulations coming into effect.

The plan is currently in Phase 2, which tightens restrictions further, after Phase 1 saw engines and vehicles tested separately. However, the story notes that some in the industry say that just one test, with engines rolled into the truck like “any other component,” is preferable to having 2.

Engines are currently tested on a dynamometer, and some, including Cummins executive director Brian Mormino, think that is the optimal approach at this time. The current system, Mormino says, preserves “spec’ing” flexibility for truck buyers, and ensures a testing process that has “repeatability,” which is to say it can be performed repeatedly.

In Phase 1, trucks are tested by way of computer modelling, with some inputs originating from on-track trials using SAE protocols, then feeding that data into the software. The only fully-integrated OEMs, Daimler and Volvo (including Mack) both argue that a single, all-inclusive test is simpler and more cost-effective than conducting two tests.

Also, the implementation of Phase 1 was relatively seamless, Mormino claims, which he attributes to the continued use of familiar regulatory tools and testing methods that have been in place for decades now. For 30 years, engine makers have tested particulates and NOx on the dyno, and easily included CO2.

“We just added CO2,” Mormino is quoted as saying in the story, “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.”

Mormino goes on to argue also that driver skills, terrain, trailer type, whether the truck is travelling on the highway or through the city, the size of the load, and many other factors also make a difference.

“That is a challenge for any type of regulation that tries to drive technology on vehicle aspects that are highly variable,” Mormino says. “And the way that the regulation attempted to deal with that is that it separated out the most certain aspect, the engine, and provided a much brighter focus on something you can repeatably and accurately measure and do so in a way where it can be enforced.”

Tony Greszler of Volvo Group, and Sean Walters of DTNA argue for the opposition.

“Our goal has always been to provide our customers with the lowest total operating costs to increase their revenues, and the most effective way to do that has been to provide better fuel efficiency,” Waters said in a quote from the story. “Regulations have interfered with this goal in the past where criteria-pollutant emissions control technology had a great negative impact on fuel economy.

Walters adds, “It’s critical that regulations to reduce fuel consumption do not in actuality result in negative impacts on real-world fuel efficiency gains, and this is where the current separate engine standard program has failed. Engine test cycles are based on historical operating data and cannot reflect changes in engine size, powertrains, or vehicle power demand and do not accurately represent the fuel used in the real-world, nor were they ever designed to do so,”

“DTNA believes the best way to ensure that the Phase 2 regulation provides a total-cost-of-operation benefit to customers is to give manufacturers the ability to focus on improving the entire vehicle as it operates on the road and in the application for which its customers want to use the vehicle. Any regulation that doesn’t give manufacturers the flexibility to meet it in the manner that works best for our customers, results in vehicles that customers can’t afford, or doesn’t provide sufficient real-world payback and risks creating a pre-buy prior to the regulation becoming effective.”

For more on this story, including all three parts of this issue, visit