Navistar International has announced it has received certification from the U.S. Environmental Protection Agency for its proprietary MaxxForce 13-liter heavy-duty big bore engines with selective catalytic reduction emissions technology, also known as SCR.

The SCR technology is from Cummins with the certification meaning the engines put out no more than 0.2 grams of nitrogen oxides per brake horsepower-hour.

The news follows the company announcing last year it was abandoning its go-it-alone approach of using Exhaust Gas Recirculation technology to meet federal emissions rules and would instead use the same technology that all other truck engine makers are employing, which requires the use of diesel exhaust fluid.

"EPA certification of our proprietary 13-liter engine with SCR completes our transition to SCR-based technology for our heavy-duty engines," said Jack Allen, Navistar executive vice president and chief operating officer. "We've reached another milestone in our emissions strategy transition and are on track to deliver our first ProStar units with our SCR-based 13-liter engines at the end of April."

The first customer deliveries of this engine are set for later this month.

Navistar introduced its first SCR-based commercial trucks for the U.S. and Canadian markets in December 2012 with the launch of the International ProStar model tractor with the Cummins ISX 15-liter engine. With the introduction of the ProStar equipped with the company's proprietary 13-liter with SCR, International says it now offers a complete line-up of SCR-based product offerings for the heavy-duty on-highway truck market.