Cummins Westport L9N

The Cummins Westport L9N is an 8.9-litre, six-cylinder inline natural gas engine for shuttle and school bus, urban transit, vocational and medium and heavy-duty truck and tractor applications. The engine is compatible with compressed natural gas (CNG), liquified natural gas (LNG), and renewable natural gas (RNG). Cummins announced the L9N at the end of 2016, and it replaced the Cummins Westport ISL G in Europe the following year. In North America, the ISL G and its 'Near Zero' counterpart have been replaced by the L9N in 2018.

The L9N uses a three-way catalyst which works by introducing a catalyst to convert the nitrogen oxides to nitrogen gas and oxygen gas, carbon monoxide to carbon dioxide, and hydrocarbons to carbon dioxide and water. The engine also features cooled exhuast gas recirculation (EGR), and spark-ignited stoichiometric combustion. The 2018 L9N is certified for EPA and CARB optional low NOx emissions standards of 0.02 g/bhp-hr, 90% lower than the previous standards.

Models

Model	Max. Power	Max. revs	Max. Torque	Emmissions Certifications
L9N 250	250 hp	2200 rpm	730 lb-ft @ 1300 rpm	EPA 2017
L9N 260	260 hp	2200 rpm	660 lb-ft @ 1300 rpm	EPA 2017
L9N 280	280 hp	2000 rpm	900 lb-ft @ 1300 rpm	EPA 2017
L9N 300	300 hp	2100 rpm	860 lb-ft @ 1300 rpm	EPA 2017
L9N 320	320 hp	2000 rpm	1000 lb-ft @ 1300 rpm	EPA 2017