2010 Emission Systems

Truck OEMS have taken two different approaches to controlling diesel emissions


Empty the DPF on a regular basis and uses good DPF cleaning equipment, advise all engine manufactures and DPF cleaning companies.

Anytime that the DPF housing is opened in normal dusty conditions, safe handling practice should be observed, says Donaldson's Schmidt. The EPA has determined that collected DPF ash is not a hazardous material, Mack's McKenna.

Never the less, when handling, capturing and containing extracted diesel soot and ash, technicians should use protective clothing and high quality dust collection equipment, recommends Taylor of FSX.

OBD SYSTEMS

For 2010 and later model year diesel engines in highway applications more than 14,000 pounds, the U.S. EPA requires OEMs to have dashboard malfunction indicator lights and diagnostic trouble codes to warn drivers of emission problems.

Similar to passenger car on-board diagnostics (OBD) systems, truck OBD systems monitor performance of the engine's major systems and emission control components, and notify the vehicle operator to any detected malfunction or deterioration with the emissions system prior to emissions exceeding a set of emissions thresholds.

All aftertreatment devices and emissions-related electronic sensors and actuators will have to be monitored for proper operation as well, says Navistar Engine's Shick.

When an issue occurs, diagnostic information must be stored in the engine's computer to assist in diagnosis and repair of the problem, condition or malfunction. EPA regulations define a "failure" as any change from as-built conditions which can raise the engine emissions beyond the regulated level.

The EPA also requires that one engine family per manufacturer be OBD-certified in the 2010 through 2012 model years, Shick points out. Beginning in 2013, all highway engines for all manufacturers must be certified to the OBD requirements.

DEF DETAILS

Diesel exhaust fluid is a simple, non-toxic and pre-mixed fluid composed of two-thirds pure water and one-third automotive-grade urea, say officials at Detroit Diesel. Experience indicates that average DEF consumption is between 2 and 3 percent of fuel consumption (2 to 3 gallons per 100 gallons of diesel fuel), depending on vehicle operation - duty cycle, geography, engine ratings, etc.

"We have found that lighter (engine) loads requires less DEF and we have seen the dosing rate drop to 2 percent," observes McKenna of Mack. "I tell everyone 3 percent. So if real world is closer to 2 percent than 3, the actual operating cost of SCR has been reduced by about 30% - not bad in today's money climate.

"We have found that heavier (engine) loads are getting markedly better fuel economy, and the dosing rate is closer to 3 percent - never above."

The manufacturers have taken precautions, at several levels, to prevent accidental filling of the DEF tanks with diesel fuel. All OEMs except Navistar are using a medium blue colored DEF fill cap and prominent markings and there are special fueling configurations. Navistar 2010 trucks will not have DEF tanks since DEF is not needed with its Advanced EGR emissions system.

"It is physically impossible to fit a standard diesel nozzle into a DEF tank, since the neck of the DEF fill tube is a smaller diameter than the diesel nozzle," Volvo's Saxman says. "The DEF inlet has been reduced to a 19-mm (about ¾-inch) diameter, from the commonly used 26-mm (about 1-inch) fuel dispenser nozzle," adds McKenna.

"As a third layer of protection, Mack offers as standard a magnetic interlock for the DEF dispenser," he continues. "We have located a magnet in the collar of the DEF tank and this releases the interlock in the DEF nozzle.

"Even when dispensing DEF, if the nozzle is removed from the filler neck, the valve release will close immediately. This alone should severely limit a ‘mis-fueling mis-adventure.'"

Other manufacturers, including DTNA, will also offer magnetic interlocks on DEF tanks as standard equipment on all vehicles.

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