Canadian engine manufacturer Cummins Westport has announced that its fourth generation natural gas engine, the ISL G, has certified to the 2010 U.S. EPA emission standard. California Air Resources Board (CARB) certification has also been secured for the ISL G.

This achievement means that natural gas engines for transit buses, refuse trucks, and other heavy vehicles have proven NOx emissions that are six times lower than their diesel counterparts. The natural gas ISL G certified to 0.2g/bhp-hr for NOx, while comparable heavy diesel engines are expected to certify to 2007 phase-in levels of 1.2g/bhp-hr for NOx emissions.

NOx contributes to poor air quality in Canadian communities as it is a precursor to the formation of smog which is harmful to human health.

Greater Vancouver's TransLink operates natural gas buses that incorporate third generation C Gas Plus engines produced by Cummins Westport.

Transportation sources are a significant cause of poor air quality. Data from Environment Canada shows that more than half of all NOx emissions in Canada came from transportation in 2002. Heavy diesel vehicles represent less than one out of every twenty onroad vehicles, yet they contribute nearly 50% of all NOx emissions from onroad sources in Canada.

Use of alternative fuel natural gas vehicles is an effective strategy to reduce NOx emissions and to lessen the harmful impact of transportation in Canadian communities.

2010 Certification for Natural Gas

Natural gas-powered refuse collection vehicles provide a lower emission alternative that reduces greenhouse gas and air quality emissions with significantly lower levels of engine noise compared to diesel-powered collection vehicles.