The ISX12 G natural gas engine delivers the strong pulling power and heavy-duty durability required for regional-haul truck/tractor, vocational and refuse applications. It features Stoichiometric cooled Exhaust Gas Recirculation (SEGR) combustion technology, which allows the use of a maintenance-free Three-Way Catalyst (TWC). Ratings range from 320 hp to 400 hp (239-298 kW) with 1450 lb-ft (1966 N•m) of peak torque. The inherent efficiency of this engine and an abundant supply of natural gas reduce operating costs, making the ISX12 G the natural choice for your fleet.

Dedicated Factory-Built Natural Gas Engine.
The ISX12 G is a dedicated, factory-built natural gas engine that is based on the Cummins ISX12 diesel engine. The ISX12 G shares many of the same parts and components as its diesel counterpart, and it operates on 100 percent clean-burning, low-cost natural gas. The ISX12 G meets current U.S. Environmental Protection Agency (EPA) and California Air Resource Board (ARB) emissions standards, and 2014 EPA greenhouse gas (GHG) and U.S. Department of Transportation (DOT) fuel consumption regulations.

The ISX12 G is a great choice for mixer, dump truck and refuse applications, with a high power-to-weight ratio and 700 lb-ft (949 N•m) of clutch engagement torque. Four refuse ratings, as well as Front Engine Power Take Off (FEPTO) and Rear Engine Power Take-Off (REPTO) options, offer power and flexibility for a wide variety of vehicles.

The ISX12 G is also the natural choice for regional-haul and LTL distribution operation trucks and tractors. Five ratings from 320 hp to 400 hp (239-298 kW), engine braking, and manual or automatic transmission capability provide trucking customers with the performance to meet fleet requirements, and the flexibility of using either compressed natural gas (CNG) or liquefied natural gas (LNG).

Advanced Combustion Technology.
The ISX12 G uses SEGR combustion with spark ignition to create a high-performance, heavy-duty natural gas engine. The cooled-EGR system takes a measured quantity of exhaust gas and passes it through a cooler to reduce temperatures before mixing it with fuel and the incoming air charge to the cylinder. SEGR results in improved power density and fuel economy versus traditional stoichiometric or lean-burn natural gas engines. This technology also enables the use of a TWC for emissions control.

Maintenance-Free Aftertreatment.
TWCs are effective, simple, passive devices packaged as part of the muffler. They provide consistent emissions control performance, are maintenance-free and can be mounted vertically or horizontally on the vehicle. The ISX12 G requires no active aftertreatment such as a Diesel Particulate Filter (DPF) or Selective Catalytic Reduction (SCR).

Natural Gas – The Fuel Choice Is Yours.
The ISX12 G operates on 100 percent natural gas, which can be carried on the vehicle in either compressed or liquefied form (CNG or LNG, respectively). The ISX12 G can also run on renewable natural gas (RNG) made from biogas or landfill gas that has been upgraded to vehicle fuel-quality. A variety of CNG and LNG tank configurations are available to meet range requirements. Consult your vehicle manufacturer for details.


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Features & Benefits

• Advanced Air Handling – Electronic control for precise air handling.
• Proven Wastegate Turbocharger – A small-frame, fixed geometry, waste gate-style turbocharger is used. A watercooled bearing housing adds durability.
• Engine Control Module (ECM) – Constantly monitors and controls engine sensors, fuel system and ignition system. Drive-by-wire throttle control. Provides OEM and end users with the ability to tailor performance of the engine to fit the vehicle’s mission. Full interface capability to Cummins INSITE™ and Cummins QuickCheck diagnostic service tools.
• High-Energy Ignition System – Provides better performance and longer service intervals, improved spark plug and coil durability and self-diagnostics. The ignition module and fuel module are controlled by a full-authority CM2180A ECM with programmable features, which is compatible with Cummins diagnostic tools.
• Accessory Belt Drive System – Self-tensioning serpentine polyvee belt accessory drive system for water pump, engine-mounted fan hub and most alternators.
• Air Intake System – Charge-air cooling reduces emissions by lowering intake manifold air temperatures.
• High-Efficiency Lube Cooler – Lowers oil temperatures, for longer engine life.
• Crankshaft – The eight-counterweight, fully balanced, high-tensile-strength steel forging has induction-hardened fillets and journals, for outstanding durability.
• Optional Engine Braking – 240 hp (180 kW) at 2100 rpm.
• Transmission – Automatic and manual options available.
• Front- and Rear Engine Power Take-Off (FEPTO and REPTO) – Options provide additional torque, for a variety of vocational applications.

ISX12 G Torque Curves

With torque curves similar to those of the ISX12 diesel within the 1150 lb-ft-to-1450 lb-ft (1559-1966 N•m) range, the ISX12 G offers comparable vehicle performance and drivability.

Gearing Recommendations
For best reliability and durability, the recommended maximum GVW for the ISX12 G in line-haul applications is 80,000 lbs (36,287 kg). Recommended gearing for line-haul applications is 1400 rpm to 1475 rpm at cruise speed for optimum fuel economy or 1450 rpm to 1500 rpm at cruise speed for a balance of fuel economy and performance. For vocational applications, gearing recommendations are 1450 rpm to 1600 rpm at cruise speed for fuel economy or 1550 rpm to 1700 rpm at cruise speed for a balance of fuel economy and performance.

Optimizing Performance with PowerSpec
Cummins PowerSpec helps you find the ideal gearing specs for engine performance or fuel economy, making it possible to tailor the operation of Cummins Westport engines to fit every customer’s application. PowerSpec can also read fault codes, and can be programmed to collect trip information for multiple drivers. PowerSpec works on both the ISL G and the ISX12 G. 

Base Warranty
The automotive base warranty for the Cummins Westport ISX12 G natural gas engine is the same as for the Cummins diesel base platform. Base warranty covers 2 years/250,000 miles (402,336 km) and 100 percent parts and labor on warrantable failures.*

Extended Coverage
For additional peace of mind, Cummins Westport offers a variety of extended coverage plans to meet every customer’s need. For details on extended coverage options, contact your local Cummins distributor or Cummins Westport representative.

Better Customer Care
Cummins Westport-powered vehicles are supported by Cummins service network, the largest and most capable in North America. Cummins authorized technicians are fully trained on Cummins Westport natural gas engines, with ready access to Genuine Cummins Parts and warranty support. For questions regarding your Cummins Westport engine, or for assistance in finding a repair facility in the United States or Canada, call Cummins Care at 1-800-CUMMINS.

Cummins Westport – The Natural Choice
Cummins Westport Inc. designs, engineers and markets 6- to 12-liter spark-ignited natural gas engines for commercial transportation applications such as trucks and buses. Our dedicated 100 percent natural gas engines are manufactured by Cummins, and are available as a factory-direct option from leading truck and bus manufacturers.

To learn more about Cummins Westport and natural gas as a transportation fuel, visit the Cummins Westport Natural Gas Academy for information, resources, videos and more – at cumminswestport.com/natural-gas-academy.