A new study released on Thursday, April 12, by the Health Effects Institute provides new insights on the advancements in clean diesel technology and ultra-low-sulfur diesel fuel, according to the Diesel Technology Forum. The study – “HEI Research Report 166: Advanced Collaborative Emissions Study (ACES) Subchronic Exposure Results: Biological Responses in Rats and Mice and Assessment of Genotoxicity” – was conducted by HEI in collaboration with the Coordinating Research Council.
The goal of ACES is to test the emissions and health effects of the new-technology diesel engines to document the improvements that have been made and to ensure that there are no unintended emissions from the new technology. The study evaluated impacts from exposure to diesel exhaust emissions on laboratory animals over various time intervals. “Overall, these results showed few biologic effects related to diesel exhaust exposure,” the ACES review panel concluded in their commentary on the study.
“As this new study illustrates, the 2007-compliant diesel technology provided historic improvements in reducing particulate and nitrogen oxide emissions,” says Allen Schaeffer, DTF executive director. “The 2010 and newer diesel technology is even cleaner with near-zero emissions. In the past decade, emissions from heavy-duty diesel trucks and buses have been reduced by 99 percent for nitrogen oxides – an ozone precursor – and 98 percent for particulate emissions, which include black carbon.”
While the study was limited to highway diesel engines like those used in commercial trucks and buses, virtually the same technologies – cleaner diesel fuel and advanced engine and emissions controls – are being phased in for all non-road engines and equipment used in construction, agriculture, mining and other industries, Schaeffer says.
“Getting to these near-zero levels of emissions is a result of the highly integrated clean diesel system – cleaner ultra-low-sulfur diesel fuel, advanced engine technologies and emissions control systems,” he says. “Not only are the engines near zero emissions, they are also achieving important gains in fuel efficiency of anywhere from two to 10 percent, bringing valuable savings to owners and operators of new clean diesel engines.”
Affected trucks include model year 2008-2018 Freightliner Cascadia and Western Star 4700, 4900, 5700 and 6900 trucks. DTNA says after hard brake applications, the brake light pressure switch may not activate the brake lights with the light application of the brake pedal.