Study Shows SCR Preferred over EGR

Jan. 14, 2009
A national research study conducted in November 2008 by Quixote Group Research indicates that purchase consideration for SCR (selective catalytic reduction) is nearly twice the level of increased EGR

With one year to go before the new EPA 2010 emissions standards for heavy-duty diesel engines go into effect, a national research study conducted in November 2008 by Quixote Group Research indicates that purchase consideration for SCR (selective catalytic reduction) is nearly twice the level of increased EGR.

The online study was fielded among small and large fleet managers, owner operators and maintenance managers on behalf of the North American Heavy Duty SCR Stakeholders Group and FactsAboutSCR.com, and has a margin of error of ±3.4%.

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When each emissions technology was briefly described, 53.4% of the 828 respondents said that they would likely consider SCR for their next truck purchase compared to 29.4% that would likely consider increased EGR. In fact, one-third of all respondents (33.7%) said they would only consider the purchase of SCR trucks compared to 10.2% that said they would only consider the purchase of trucks with increased EGR.

“Based on purchase consideration, it appears that the key benefits provided by the SCR technology, which include fuel savings and fewer active regenerations, outweigh the added step of keeping diesel exhaust fluid tanks filled,” said Chuck Mattina, president of Quixote Group Research. “Engine OEMs committed to SCR should focus on clearly communicating these meaningful benefits to prospective buyers. SCR is clearly the frontrunner at this point in time, and we would expect the battle to begin shifting from SCR versus increased EGR to who will have the best SCR system available on January 1, 2010.”

The study also found that many in the trucking industry are unsure of the standards or the specific benefits provided by the two competing technologies. According to the research:

  • 60% of the respondents understand that nitrogen oxide (NOx) is specifically included in the new EPA 2010 standards (see chart 2 attached).
  • Nearly half of the respondents said that they do not know which emissions technology – SCR or increased EGR – will deliver key benefits, such as fuel savings and fewer active regenerations.

The majority of suppliers of diesel-powered heavy duty commercial engines and vehicles, including Detroit Diesel, Daimler Trucks North America, Cummins, Volvo Trucks, Mack Trucks, Peterbilt and Kenworth, plan to utilize SCR to meet the EPA 2010 standards, which limit NOx levels to no more than 0.2 g/bhp-hr (grams per brake horsepower-hour).

SCR emissions technology works after engine combustion, and uses diesel exhaust fluid, which will be available for sale at truck stops, to convert NOx emissions into pure nitrogen and water vapor, two natural components of the air we breathe. Navistar is the only non-SCR supplier.

To comply with the 2010 standards, the company plans to utilize emissions credits combined with increased EGR, which is an in-cylinder approach that utilizes high-pressure fuel injection, air management and optimized combustion strategies to reduce NOx emissions.