North American Bus Industries, Inc. (NABI) has ordered 260 compressed natural gas (CNG) Cummins Westport (CWI) ISL G engines for CompoBus buses.
The NABI CompoBus is a 45-foot vehicle made from a lightweight composite material that weighs roughly the same as the company’s traditional 40-foot bus, enabling it to provide a lower operating cost per passenger mile as compared to buses with traditional steel structures.
The ISL G surpasses EPA 2007 phase-in levels and meets 2010 emission standards of 0.2 g/bhp-hr NOx and 0.01 g/bhp-hr PM. Based on the Cummins ISL, the ISL G leverages cooled Exhaust Gas Recirculation (EGR) with stoichiometric combustion allowing for the use of a three way catalyst, which is maintenance free and is in common use in passenger cars.
In addition to delivering ultra-low emissions, the ISL G, with ratings from 250 to 320 horsepower, delivers increased thermal efficiency and more than 30% higher low-speed torque compared with today’s CWI Plus engines.