Naturally Better. Cummins Westport ISL G Natural Gas Engine. There are over 40,000 Cummins Westport natural gas engine-equipped vehicles performing cleanly and reliably today. Interest in natural gas engines is steadily growing throughout North America, with Cummins Westport natural gas engines widely recognized for their technological leadership in urban transit fleets. The ISL G combines all the advantages of clean burning natural gas with no compromise in power or torque. 

Premium performer Unique among engine platforms, the 8.9-litre L Series combines the robust characteristics of a higher displacement, heavy-duty engine with the efficiency and lower operating costs of a smaller, midrange engine. This fusion of attributes gives the ability to power a remarkably broad range of vehicles, while delivering premium levels of performance and has earned a reputation for dependability unsurpassed in industry, tailored to every application.  

Moving Forward To Near Zero​ Latest design enhancements to the L9N natural gas engine have achieved close-to-zero emission levels, below that of the Euro VI standard. This leap forward is achieved while retaining the simplicity of a passive ‘fit and forget’ aftertreatment. Sharing the same engine block as the high-strength L9 diesel brings the benefit of 80 percent component commonality between the two engines. Ideally suited for bus, coach and truck applications with cleaner and quieter operation.​