Diesel-powered engines remained the dominant fuel powering newly registered commercial trucks in 2013, as vehicle owners continued pushing adoption of natural gas powerplants, according to Polk.

Diesel engines are powering 77.9 percent of the commercial trucks registered in Class 3-8 in 2013, a decline from the 81 percent of newly registered diesels in 2012.

The modest decline came as a result of an increase in Ford and Chevrolet gasoline and flex fuel engines mostly in Class 3 vehicles, according to a Polk report released Wednesday.

Overall, new commercial vehicle registrations reached 572,478 in 2013. In the government sector, registrations continued to advance from 2011 lows as federal, state, and local agencies added 58,049 vehicles into service. Government agencies registered 52,155 vehicles in 2011.

Diesel engine market penetration fell in all six gross vehicle weight classes. The sharpest decline came in medium-duty Class 6, where it fell to 73.6 percent from 81.2 percent.

At the same time, newly registered commercial trucks with dedicated natural gas engines rose 5.8 percent from 2012. There were 4,330 factory installed compressed natural gas engines during 2013.

Cummins retained its dominant share of CNG engine installs with 89.3 percent of factory installed natural gas engines. Westport accounted for 4.8 percent of the installs.

Read the full report here.

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