The Cummins Westport (CWI) 2007 ISL G natural gas engine (earlier post) has received formal certification from the US Environmental Protection Agency (EPA) that it surpasses EPA 2007 phase-in levels and meets the 2010 emission standards of 0.2 g/bhp-hr NOx and 0.01 g/bhp-hr PM.
Based on the Cummins ISL, the 8.9-liter ISL G leverages Cummins’ 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, will deliver increased thermal efficiency and more than 30% higher low-speed torque compared with today’s CWI Plus engines.
Cummins Westport has already logged more than 500 orders for the ISL G from US transit organizations, including Sacramento Regional Transit and the Orange County Transportation Authority (OCTA).
The ISL G is the world’s first heavy duty engine for urban bus and truck applications to be certified to the 2010 EPA standard. With improved low end torque and maintenance-free aftertreatment, the ISL G will deliver diesel-like performance and reliability and the opportunity for customers to take advantage of the lower cost of natural gas.—Guan Saw, President of Cummins Westport