With six months to go before the new EPA 2010 emissions standards for heavy duty diesel engines go into effect, a national research study shows that purchase consideration for SCR (selective catalytic reduction) remains higher than increased EGR.

More than half (51.2%) of all respondents are likely or very likely to consider SCR for their EPA 2010 engine purchase compared to 31.2% that are likely or very likely to consider increased EGR. Overall purchase consideration for the two emissions choices have remained statistically unchanged since the last survey was conducted in November 2008.

The online study was conducted by Quixote Group Research among owners and operators of Class 8 heavy duty trucks on behalf of the North American SCR Stakeholders Group and FactsAboutSCR.com.

Three-quarters (75.4%) of all respondents rated fuel efficiency as very important to the decision to purchase an EPA 2010 compliant engine, and nearly half (48.8%) of all respondents now correctly relate fuel savings of approximately 3% to 5% with SCR, which is up from 38.7% in November 2008.

Proven technology (production trucks and engines have been proven on-the-road) was rated as very important to the purchase decision by 70.1% of all respondents. Engine optimization and scheduled maintenance required by the 2010 technology were rated very important by 59.6% and 59.0% of all respondents, respectively. The weight added by the 2010 emissions technology had a significantly lower level of importance (44.2%) to the decision making process.

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 use 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). Navistar is the only non-SCR supplier. To comply with the 2010 standards, the company plans to use emissions credits combined with increased EGR, which is an in-cylinder approach that uses high-pressure fuel injection, air management and optimized combustion strategies to reduce NOx emissions.

The online study was developed by Quixote Group Research and was designed to support the efforts of the Communications Subcommittee of the North American SCR Stakeholders Group. Sample for the study, which was fielded in May 2009, was provided by Heavy Duty Trucking magazine. A total of 1,603 responses were collected, resulting in a margin of error of ±2.4%.