Medium Trucks, School Buses, Sweepers, Yard Hostlers
Among Target Markets for 260 Horsepower Spark Engine
Cummins Westport anticipates limited production in 2015 and full production in 2016 of the ISB6.7G – a dedicated-natural gas version of the Cummins ISB diesel offering 260 horsepower at 660 foot-pounds torque.
The new spark-ignition engine is expected to boost the market for compressed natural gas-fueled school buses (especially Type C) and trucks ranging from heavy beverage vehicles down to package delivery, and for such vocational vehicles as sweepers and yard hostlers.
Like the 20,000-unit-plus ISL G (8.9 liters) and the now-commercial ISX12 G (11.9 liters), the ISB6.7G will be a stoichiometric engine with three-way catalyst, boosting the competitive position of natural gas versus diesel because no SCR or other additional aftertreatment will be required.
‘Common Components, Fewer Unknowns’
In addition to California and U.S. EPA certifications, the engine will meet 2017 greenhouse gas emission standards, as well as Euro VI, Cummins Westport product management and planning director Stephen Ptucha said at the NGV Tech Forum on Long Island Tuesday. A key program goal is for 5% to 10% better fuel economy than Cummins Westport’s 5.9-liter engine.
Engineers are also working toward “common components among engines,” Ptucha said at NGVTF – engine controls will match those of the ISL G and ISX12 G.
“There are fewer unknowns when you’re going through it the third time,” outgoing Cummins Westport president Jim Arthurs said on the diesel-engine-to-natural-gas-engine development process.
Thomas Built Is Participating
“We’re on track,” he told F&F. “We’ll be building some alpha engines in the spring. We’ll have engines in trucks this year.”
Arthurs declined to mention OEM partners for ISB6.7G development, but Thomas Built said in 2012 that it wants the engine in a new Type C bus (F&F, October 23, 2012). Like Freightliner, an early OEM partner for the ISX12 G, Thomas Built is a unit of Germany’s Daimler.
Cummins Westport, Stephen Ptucha, 604-718-2024; email@example.com; www.cumminswestport.com
Thomas Built (product development), Jed Routh, 336-841-5765; firstname.lastname@example.org
Thomas Built (sales), VP Ken Hedgecock, 336-841-5756; email@example.com; www.thomasbus.com
Source: Fleets & Fuels interview and at NGVTF