External combustion

| April 30, 2009

One of the advantages of the 2010 lineup is improved fuel economy even when drivers aren’t as skilled or focused on driving for fuel efficiency, said Steve Charlton, vice president of heavy-duty engineering. “Our heavy-duty engines for 2010 have a large sweet spot due to the low-temperature NOx conversion capability of the copper-zeolite catalyst, which means that these engines are extraordinarily driver-friendly.”

Detroit’s new 15.6-liter slated for Western Star
The new Detroit Diesel DD16 engine will be in production for the Western Star 4900 series in March 2010 and the Western Star 6900 in July 2010, Western Star Trucks announced. Detroit Diesel said the DD16 is its most powerful engine and will be equipped with BlueTec emissions technology.

The DD16 displaces 15.6 liters and is suited for owner-operators, small fleets and specialty applications. The DD16 is the third in a series of heavy-duty engines from Detroit Diesel that covers three displacement categories: 13 liters, 15 liters and 16 liters.
David Siler, director of marketing for Detroit Diesel, said the DD16 will be offered with output and multitorque power ratings from 1,750 to 2,050 lb.-ft. torque and 475 to 600 hp.

Volvo, Mack promote SCR advantages
Volvo and Mack trucks equipped with engines that comply with tighter 2010 U.S. Environmental Protection Agency emissions regulations will have many advantages over current diesels, said spokesmen for the truck manufacturers.

One distinctive advantage Volvo claims is that its engines with selective catalytic reduction systems will not require active regeneration of diesel particulate filters during normal highway operating conditions, said Scott Kress, senior vice president of sales and marketing for Volvo. Kress said that thanks to the 2010 integration of Volvo’s SCR and DPF technologies, passive regeneration cycles will eliminate the need to inject diesel fuel into the DPF to oxidize accumulated soot.

“This, of course, results in reduced fuel consumption, reduced thermal cycling of expensive catalysts and lower overall operating costs,” he said. “It also relieves the driver of another responsibility – having to keep track of when an active regeneration needs to take place – and allows the truck to operate in areas where a recently cycled, and hot, DPF would be a safety hazard – indoors or in refineries, for example.”

Kress said the ability to passively regenerate DPFs depends on having the correct concentration of nitrogen oxides in the hot exhaust stream flowing into the unit’s filter. NOx enables passive regeneration, and SCR eliminates NOx from the exhaust after it flows through the DPF.

At a Mack press conference, Dave McKenna, director of powertrain sales and marketing, doused a lit candle with diesel exhaust fluid to prove that “DEF is not flammable.” The dramatic gesture was part of McKenna’s way of combating any concerns over the safety of SCR technology.

“SCR is simply the most viable and cost-effective way to meet EPA 2010,” McKenna said. “Other technologies, such as diesel NOx reduction systems, are unproven in engines with displacements larger than six liters, and diesel NOx absorbers have proven to be unviable. You can use massive EGR with EPA credits, but once those credits are gone, they are gone.”

McKenna said that based on a diesel fuel price of $2.42 a gallon, fleets can expect to save $1,655 a month on fuel by running Mack SCR diesel engines compared to pre-2010 engines. That figure includes the cost of DEF, he said.
- Linda Longton, John Baxter, Avery Vise and Jack Roberts contributed to this report

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