A LOW EMISSION VEHICLE

摘要

A low emission vehicle operates an internal combustion engine with lean air fuel ratios over at least a portion of its operating load range. The vehicle satisfies EURO IV emission requirements with just a three way catalyst and without any NOX storage capability in the exhaust after treatment system. An electronic control unit is programmed to operate the engine such that 80% or less of any tail pipe NOX mass emitted by the vehicle is generated during lean operation of the engine whereby the vehicle satisfies the EURO IV emission requirements.