Navistar International's upcoming MaxxForce 15 diesel will combine "iron" components from Caterpillar's C15 with Navistar's 2010-spec fuel and air-management systems and electronic controls.


Navistar will assemble the MaxxForce 15 at its plant in Huntsville, Ala., but it won't be
available for a year or more.

The 15.2-liter (928-cubic-inch) MaxxForce 15 - which wags have dubbed the "Maxxipillar" - will be Navistar's largest big-bore diesel, eventually replacing the currently offered C15 and ISX in certain Class 8 International trucks and tractors sold in the U.S. and Canada. The MF 15 will have seven on-highway and four vocational ratings, from 435 to 550 horsepower and torque of 1,550 to 1,850 pounds-feet.

Sometime in 2010 it will join the rest of the MaxxForce lineup, including the now-available 10.5- and 12.4-liter MaxxForce 11 and 13 for Class 8 trucks.

Following Navistar's go-it-alone approach to meeting 2010 emissions limits, the MaxxForce 15 will not use selective catalytic reduction (SCR) but its Advanced EGR (exhaust-gas recirculation) system, with higher amounts of EGR and enhanced in-cylinder combustion techniques to cut oxides of nitrogen and other pollutants.

A-EGR for this engine also includes common-rail, high-pressure, multi-event fuel injection, double turbocharging, and two coolers each for inlet air and EGR. As with current 2007-spec engines, the MF 15's exhaust system will have a combined oxygen catalyst and diesel particulate filter.

Because the MF 15 won't be ready until later in 2010, Navistar will continue offering Cummins' 15-liter ISX into the new year. But it won't have SCR, as Cummins will sell it to other truck builders. Navistar says it will use the current '07-spec ISX, which it will apparently do by stockpiling the pre-'10 engines through December and installing them in International trucks until the MF 15 is ready. Limited stockpiling is legal under Environmental Protection Agency rules.