CHICAGO. Navistar rolled out three MaxxForce proprietary diesel engine families for a ride-and-drive event here, all using the company’s “advanced EGR” technology to meet the new 2010 federal emissions regulations. The engines – two medium-duty models and its “Big Bore” heavy-duty 11- and 13-liter – have finished durability and performance testing and will be submitted for certification by the U.S. Environmental Protection Agency starting in December, according to Ramin Younessi, Navistar Truck Group vp of product development&d strategy.
Work to develop a 2010-compliant heavy-duty 15-liter diesel based on Caterpillar’s current C15 is also continuing, with availability scheduled for sometime next Spring, according to Younessi.
Navistar will build 1,500 trucks with its new engines, including “a few 15-liter versions” before the end of the year and deliver them to customers in the first quarter of 2010, according to Jim Hebe, sr. vp -- North American Sales. The early builds will give users a chance to test Navistar’s singular approach to meeting 2010 emissions requirements.
Navistar is the only truck maker that will not use selective catalytic reduction (SCR) aftertreatment and diesel emissions fluid (DEF) to reduce NOx to the new federal limits of 0.2 g/bhp-hr. Instead its advanced EGR approach controls NOx formation within the combustion chamber and does not require users to periodically refill vehicle tanks with DEF. It is also using emissions credits banked since 2007 to certify its engines at a 0.5 g/bhp-hr. NOx level. EPA rules allow the use of credits until 2012, at which time Navistar says it will certify engines at the lower NOx level.
The 2010 MaxxForce Big Bore 11- and 13-liter family will be available in ratings of 330 to 475 HP. Technical features include an integrated Jake Brake, a new single electronic control unit (ECU), twin turbochargers with fixed vanes, a high-pressure common-rail fuel injection system, and a two-stage exhaust gas recirculation (EGR) cooler.
The engine has finished high-altitude and cold-weather testing at “EPA compliant” emissions levels of 0.4 to 0.5 grams of NOx, according to Younessi. Performance in the tests was the same as current engines, and Navistar expects fuel economy to be “the same, if not better” for trucks carrying the 2010 versions of the Big Bore diesels, he said.
Intended for medium-duty trucks, severe-duty applications and buses, the 2010 MaxxForce DT/9/10 family of inline-6 diesels comes in two displacements – 7.6- and 9.3-liter – with rating ranging from 215 to 330 HP. It features a 10% increase in fuel injection pressure, a new cylinder head design and single EGR cooler. Carryovers from earlier models include dual turbochargers, a single ECU, and scheduled maintenance intervals.
While performance of the 2010 DT varies by rating, “all perform the same or better than ’07-compliant versions,” said Younessi.
At the smallest end of its engine line up for 2010, the MaxxForce 7 6.4-liter V8 has actually shown a 1% to 3% improvement in fuel economy in Navistar’s testing, Younessi pointed out. In addition to its advanced EGR emissions control system, the 2010 version of the popular V8 features increase fuel pressures, dual turbos, a single ECR cooler and a more powerful ECU. Its power ratings range from 200 to 300 HP.
(Video: Lead engineer Priyankar Balekai points out the major features of the 2010 MaxxForce 7)
