Navistar International has received certification from the U.S. Environmental Protection Agency for its 2011 model year MaxxForce DT mid-range diesel engine at 0.39 g/bHpHr NOx using Navistar's in-cylinder NOx reduction technology.

This certification represents a 22 percent emissions reduction from the original 0.50g/bHpHr certification, and the company notes that it demonstrates progress to achieving the 0.20g/bHpHr standard through base engine and in-cylinder optimization.

"Getting to 0.2g NOx through our in-cylinder technologies has always been part of our plan and remains so today," said Ramin Younessi, group vice president, product development and business strategy. "Our technology path continues to be a seamless process for our customers where the only thing that changes for them is the EPA label affixed on the engine."

Navistar has also received 2010 emissions certification from the EPA and the California Air Resources Board for its 2011 MaxxForce 15 big-bore diesel engine. The company launched full-scale production of the MaxxForce 15 at its Huntsville, Ala., engine plant in mid-January and the first 2011 model year International ProStar+ units with MaxxForce 15 are now making their way into customers' hands, says the company.

In addition, Navistar also recently submitted its MaxxForce 13 at 0.20g NOx for EPA certification. The company intends to phase-in its engines at progressively lower NOx emissions levels (0.4g NOx, 0.35g NOx, 0.3g NOx, 0.25g NOx, etc.) in the years ahead in an effort to make emissions compliance as seamless as possible to its customers.

Navistar is able to take this graduated approach because in previous years, it generated credits with the EPA for some of its smaller engines that were cleaner than the required emissions standard.

All International brand on-highway commercial vehicles and IC Bus brand school and commercial buses for the North American market are powered by MaxxForce engines with MaxxForce Advanced EGR emissions technology.