Engine Technologies

Natural gas engine technologies offer power, torque, and fuel efficiency similar to diesel engines. Canadian companies are global leaders in the supply of natural gas engines. The first heavy natural gas engine was developed in Ontario in the mid-1980s for transit bus use. Engine technologies for medium and heavy natural gas vehicles have steadily improved since then.

Cummins Westport has sold more than 35,000 engines since it was established in 2001 as a joint venture between Westport Innovations and Cummins. Westport Innovations developed the world’s first natural gas engine that matches the efficiency of a diesel engine. Today, two natural gas engines are available for medium and heavy factory-built natural gas vehicles.

Cummins Westport ISL G

ISL G Engine

8.9 L, 250–320 hp
660–1000 ft-lb torque
EPA & CARB 2013
CNG or LNG
Spark-ignited

Cummins Westport ISX12 G

Cummins Westport ISX G

11.9 L, 320-400 hp
1150-1450 ft-lb torque
EPA & CARB 2013
CNG or LNG
Spark-ignited

The ISL G and ISX12 G engines are factory-built 100% natural gas engines and are available from leading truck and bus manufacturers. Fuel can be carried on board the vehicle as either compressed natural gas (CNG) or liquefied natural gas (LNG). These fourth generation engines share many of the same parts and components with their diesel counterparts, the Cummins ISL and the ISX. The two engines operate within 12-15% of the fuel efficiency of similar diesel engines. This efficiency difference is typically  more than offset by a lower natural gas fuel cost resulting in a lower cost per kilometre.

Fleets will reduce their greenhouse gas emissions by up to 20% using ISL G- and ISX12 G-equipped vehicles. Trucks and buses with these engines do not require diesel particulate filters or selective catalytic reduction to meet emissions standards. The expense associated with purchasing diesel exhaust fluid can be eliminated. The ISL G and ISX12 G have a simple maintenance-free three-way catalyst.

As of October 2013, Westport Innovations no longer offers its 15 litre high pressure direct injection engine to the market. Westport is changing its approach, so that they will now directly license their technology to truck manufacturers. Volvo is the first OEM who is expected to bring a 13 litre natural gas engine to the market for highway tractors in 2015 based on the Westport technology.