Aftermarket

EPA, CARB Workshop Examines Driver Defeat of SCR Engines

July 22, 2010

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Changes to the EPA's 2010 emissions regulations relating to selective catalytic reduction technology are being proposed as a result of a suit brought against the EPA by Navistar. During a California workshop Tuesday, both sides had a chance to present comments.

The Navistar lawsuit challenged guidelines issued during the implementation of the SCR technology. Navistar argued that the guidelines were in effect a rule and that the correct procedure had not been followed in the rulemaking
At issue is the question of keeping diesel exhaust fluid in the tank for proper functioning of selective catalytic reduction.
At issue is the question of keeping diesel exhaust fluid in the tank for proper functioning of selective catalytic reduction.
process. When EPA agreed to review and issue new guidelines, Navistar agreed to drop the lawsuit.

The EPA and the California Air Resources Board presented proposed rule changes during CARB's heavy-duty diesel Selective Catalytic Reduction workshop. After a nearly two-hour presentation, comments were presented by Navistar, Volvo Powertrain, Mack and Volvo Corporate and Cummins.

The proposals are for ways to make the driver add diesel exhaust fluid - "inducement strategies" if the DEF tanks get to very low levels of the reagent, and to keep them from running without fluid or with incorrect fluid, or tampering with the SCR system.

Navistar's president Jack Allen presented his company's evidence of the ability of drivers to defeat SCR aftertreatment. This would permit post-2010 trucks running the SCR technology to continue to operate without DEF, emitting 10 times or more the regulated amount of NOx (0.2 g per hp-hr). Navistar uses Advanced Exhaust Gas Recirculation to meet the EPA 2010 emissions requirements and is the only manufacturer not pursuing SCR technology.

The company's concerns were presented in a short video, "License to Pollute," that was introduced by vice president of government relations, Patrick Charbonneau. In the video, Navistar showed three vehicles that could be driven either without the diesel exhaust fluid in the urea tank or with water substituting for the DEF.

The competition's response

But making changes to the rule only six months after it went into effect would not be fair nor easy to meet. That was the gist of comments by Steve Berry, director of emission strategy from Volvo Powertrain, John Mies, Mack and Volvo vice president of corporate communications,and Bob Jorgensen from Cummins Environmental Management Group. These three all spoke to the difficulty of making a rule change only six months into the new EPA 2010 emissions regime, especially in view of the proposed changes becoming effective as early as January 2011.

Mies was the most outspoken of the SCR proponents.

"In the midst of all this (SCR) good news for our industry and the environment, we learned a few weeks ago - not even six months after the implementation date for the new technology - that the regulations we followed in good faith were to be reconsidered," he read from his prepared statement. "And why? In large part because of concerns being raised by a single competitor," referencing the Navistar lawsuit and the evidence in the video.

He went on to criticize Navistar and the EPA. He accused Navistar of using the courts to achieve its commercial purpose and the EPA of colluding. He laid out the following about Navistar:

"A competitor that says it is concerned about the environment, but whose U.S. '10 engines will emit two and a half times the 2010 NOx standard, and are only certifiable with emissions credits.

"A competitor that said it was ready for the new standards, yet lobbied for a delay in implementation, and when that failed, resorted to lawsuits against the regulators.

"A competitor that apparently believes that most of its customers, and the trucking industry as a whole, are hell-bent on illegal circumvention of emissions controls.

"A competitor that has only been able to compete in the market this year by selling thousands and thousands of pre-2010 engines.

"A competitor that, if it succeeds in convincing you to change the rules, will turn around and tell customers the rules are bad for their business, and use them as a selling point for their own higher-emitting engines."

Summing up, Mies said: "The fact is that a Volvo truck running at 0.2 grams is and will continue to be much better for the environment than a Navistar truck running at 0.5 grams - and no amount of changes to the inducement strategies will change that."

Jorgensen commented that Cummins had produced 12,000 engines in the first six months of the year offering a 5 percent better fuel economy and that not only were they better for the environment for the low NOx emissions, but the fuel economy also meant lower greenhouse gas emissions and less dependency on foreign oil. He also commented that the inducement strategy pursued by Cummins was a 25 percent reduction in torque when no DEF is present.

License to Pollute

In the Navistar video, the three trucks - a Freightliner Cascadia with DD15 engine, a T660 with Cummins ISX and a Dodge Ram Class 4 pickup with Cummins B Series diesel - were all run out of DEF. The inducement strategies for the different vehicles (only the Cascadia and Dodge were featured in the video) duly played out with warning messages, dash lights and chimes reminding the driver to refill with the DEF.

In the case of the featured trucks, adding plain water to the DEF tank defeated the severe inducement strategies and allowed the vehicles to be restarted and driven normally, said the commentary. In the case of the Cascadia, the truck was driven a total of 11,000 miles by the time the video was complete with no detriment to the performance, allowing it to be driven up to 55 mph with no impediment and at the full 80,000 pounds GCW. According to Charbonneau, the Cascadia has now completed in excess of 13,000 miles, still with no DEF in its tank.

Running with pure water instead of DEF meant the Cascadia was emitting 10 times the regulated NOx, the Cummins-powered T660 was 30 times the NOx according to EnSIGHT, the third-party testing agency featured in the video. This was the only reference made to the Kenworth. Testing had only been completed in the last 30 days, said Charbonneau.

Further, Navistar alleged that European experience shows that at low exhaust temperatures the DEF does not produce the NH3 (Ammonia) that is essential to the catalytic reduction technology, saying that these low exhaust temperatures may well be seen in urban, stop-start driving conditions.

"Truck owners are paying a substantial price to comply with 2010 NOx requirements," said Allen. "They, and the public, deserve to know that the new equipment they are purchasing actually works as promised to curb pollution. It's obvious, however, that these trucks can operate effectively without liquid urea, and that under these and other conditions, SCR NOx emission control is turned off. We're calling on the EPA and CARB to assure that all vehicles, not just ours, work when they are supposed to be working."


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