Radical ‘Clean Diesel' Truck Engine Approval Expected Soon

Navistar International Corp. has submitted test data to the U.S. Environmental Protection Agency for its first on-road truck engine to meet federal clean-diesel mandates without using selective-catalytic-reduction technology (SCR). Regulators' approval of the 13-liter MaxxForce engine, a necessary step to ensure that Navistar's tailpipe controls work, is expected in three to six months, says the Warrenville, Ill.-based manufacturer. Navistar has objected to SCR, which requires a periodic fill-up with urea, claiming truckers don't want the hassle. The manufacturer is the sole supplier that uses only exhaust-gas recirculation to lower its smog output.