Cummins Westport

The Natural Choice

ISX12 G
Heavy-Duty Natural Gas Truck Engine
The Natural Choice.
ISX12 G Heavy-Duty
Natural Gas Truck Engine.
The Cummins Westport ISX12 G natural gas engine Advanced Combustion Technology.
delivers the strong pulling power and heavy-duty
The ISX12 G features Cummins Westports Stoichiometric
durability required for line-haul and regional-haul truck/
cooled Exhaust Gas Recirculation (SEGR) combustion
tractor, vocational, refuse and motorcoach applications.
technology with spark ignition, leveraging Cummins
Ratings range from 320 hp to 400 hp (239-298 kW)
proven EGR technology to create a high-performance,
with 1450 lb-ft (1966 Nm) of peak torque. The inherent
heavy-duty natural gas engine. The cooled-EGR system
efficiency of this engine, and an abundant supply of
takes a measured quantity of exhaust gas and passes it
natural gas, reduces operating costs, and makes the
through a cooler to reduce temperatures before mixing
ISX12 G the natural choice for your fleet.
it with fuel and the incoming air charge to the cylinder.
This results in improved power density and fuel economy
Dedicated Factory-Built Natural Gas Engine.
versus traditional stoichiometric or lean-burn natural gas
The ISX12 G is a dedicated, factory-built natural gas engines. This technology also enables the use of a Three-
engine that is based on the Cummins ISX12 diesel Way Catalyst (TWC) for emissions control.
platform, and shares many of the same parts and
components as its diesel counterpart. The ISX12 G Maintenance-Free Aftertreatment.
meets current U.S. Environmental Protection Agency
TWCs are effective, simple, passive devices packaged
(EPA) and California Air Resources Board (ARB) emissions
as part of the muffler. They provide consistent emissions-
standards, and EPA greenhouse gas (GHG) and U.S.
control performance without filter regeneration activity,
Department of Transportation (DOT) fuel consumption
are maintenance-free and can be mounted vertically or
regulations.
horizontally on the vehicle. The ISX12 G requires no active
The ISX12 G is the natural choice for line-haul, regional- aftertreatment such as a Diesel Particulate Filter (DPF) or
haul and Less than Truckload (LTL) distribution operation Selective Catalytic Reduction (SCR).
trucks and tractors.

Five ratings from 320 hp to 400 hp (239-298 kW),

combined with engine braking and manual, automatic
and automated manual transmission capability, provide
trucking customers with the performance to meet fleet
requirements.

The ISX12 G is also a great choice for mixer, dump truck

and refuse applications, with a high power-to-weight ratio
and 700 lb-ft (949 Nm) of clutch engagement torque.
Four refuse/vocational ratings, as well as Front-Engine Natural Gas The Fuel Choice Is Yours.
Power Take-Off (FEPTO) and Rear-Engine Power Take-
The ISX12 G operates on 100 percent
Off (REPTO) options, offer power and flexibility for a wide
natural gas, which can be carried on
variety of vehicles.
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. To meet engine fuel requirements
under a variety of load conditions, the engine requires the
fuel storage system to provide at engine fuel pressure of
rated conditons between 60 psi and 150 psi.
 Design Architecture. Coil-on-Plug Ignition

Wastegate Turbocharger

EGR Valve

4-Valve Cylinder Head

Fuel Module

High-Energy Ignition System

Engine Control Module (ECM)

Features And Benefits.

Advanced Air Handling Electronic control for precise air Accessory Belt Drive System Self-tensioning serpentine
handling. polyvee belt accessory drive system for water pump,
engine-mounted fan hub and most alternators.
Proven Wastegate Turbocharger A small-frame, fixed-
geometry, wastegate-style turbocharger is used. A water- Air Intake System Charge-air cooling reduces emissions
cooled bearing housing adds durability. by lowering intake manifold air temperatures.

Engine Control Module (ECM) Full-authority CM2180A High-Efficiency Lube Cooler Lowers oil temperatures, for
ECM constantly monitors and controls engine sensors, longer engine life.
fuel system and ignition system. Drive-by-wire throttle
Crankshaft The eight-counterweight, fully balanced,
control. Provides OEM and end users with the ability
high-tensile-strength steel forging has induction-hardened
to tailor performance of the engine to fit the vehicles
fillets and journals, for outstanding durability.
mission. Full interface capability to Cummins INSITE and
Cummins QuickCheck diagnostic service tools. Optional Engine Braking 240 hp (178 kW) at 2100 rpm.

High-Energy Ignition System Improved Ignition Control Transmission Automatic, manual and automated manual
Module (ICM) provides better performance and longer options available.
service intervals, improved spark plug and coil durability
Front- and Rear-Engine Power Take-Off (FEPTO and
and self-diagnostics. The ICM is controlled by the full-
REPTO) Options provide additional torque, for a variety
authority CM2180A ECM.
of vocational applications.
ISX12 G Ratings

Engine Advertised Peak Torque Governed

Model hp (kW) lb-ft (Nm) @ rpm Speed
Line-Haul Truck Applications
ISX12 G 400 400 (298) 1450 (1966) @ 1200 2100 RPM
ISX12 G 385 385 (287) 1350 (1830) @ 1200 2100 RPM
ISX12 G 350 350 (261) 1450 (1966) @ 1200 2100 RPM
ISX12 G 330 330 (246) 1250 (1695) @ 1200 2100 RPM
ISX12 G 320 320 (239) 1150 (1559) @ 1200 2100 RPM
Refuse Truck Applications
ISX12 G 350R 350 (261) 1350 (1830) @ 1200 2100 RPM
ISX12 G 350R 350 (261) 1450 (1966) @ 1200 2100 RPM
ISX12 G 330R 330 (246) 1250 (1695) @ 1200 2100 RPM
ISX12 G 320R 320 (239) 1150 (1559) @ 1200 2100 RPM
Motorcoach Applications
ISX12 G 400 400 (298) 1450 (1966) @ 1200 2100 RPM

ISX12 G Specifications
ISX12 G Maintenance Intervals
Maximum Horsepower 400 HP 298 kW
Maintenance Item Miles/Kilometers Hours Months
Peak Torque 1450 LB-FT 1966 Nm
Spin-On Fuel Filter Daily Check
Governed Speed 2100 RPM
Oil And Filter*^ 25,000 MI 500 6
Clutch Engagement Torque 700 LB-FT 949 Nm
40,000 KM
Type 4-cycle, spark-ignited,
Coolant Filter** 75,000 MI 1,500 12
in-line 6-cylinder,
120,000 KM
turbocharged, CAC
Spin-On Fuel Filter* 50,000 MI 1,000 9
Engine Displacement 726.2 CU IN 11.9 LITERS
80,000 KM
Bore and Stroke 5.11 IN x 5.91 IN 130 MM x 150 MM
Spark Plugs* 75,000 MI 1,500 12
Operating Cycles 4 120,000 KM
Oil System Capacity 12 U.S. GALLONS 45.4 LITERS Overhead 75,000 MI 1,500 12
Coolant Capacity 26.5 U.S. QUARTS 25.1 LITERS Adjustment* 120,000 KM

System Voltage 12 V Engine Brake 300,000 MI 6,000 24

Adjustment 480,000 KM
Net Weight (Dry) 2,650 LB 1,202 KG
Standard Coolant 300,000 MI 6,000 24
Fuel Type CNG/LNG/RNG
480,000 KM
Aftertreatment Three-Way Catalyst (TWC)
Air Cleaner/Element Follow vehicle manufacturers
published recommendations
*Assuming normal duty cycle/based on 50 mph (80 kph) average speed.

**Do not charge if Supplemental Coolant Additive (SCA) above 3.

 ISX12 G Torque Curves. Base Warranty.
1500 The automotive base warranty for the
Cummins Westport ISX12 G natural
1400
gas engine is the same as for the
1300
Cummins diesel base platform. Base
Engine Torque (LB-FT)

1200 warranty covers 2 years/250,000 miles (402,336 km) and

1100 100 percent parts and labor on warrantable failures.*
ISX12 G 320/1150
1000
ISX12 G 330/1250

900 ISX12 G 385/1350

800
ISX12 G 350/1450 Extended Coverage.
ISX12 G 400/1450
700 For additional peace of mind, Cummins Westport offers
600 800 1000 1200 1400 1600 1800 2000 2200
a variety of extended coverage plans to meet every
Engine Speed (RPM)
customers need. For details on extended coverage
With torque curves similar to those of the ISX12 diesel, options, contact your local Cummins distributor or
within the 1150 lb-ft-to-1450 lb-ft (1559-1966 Nm) range, Cummins Westport representative.
the ISX12 G offers comparable vehicle performance
and drivability.
Better Customer Care.
Cummins Westport-powered vehicles
Gearing Recommendations.
are supported by Cummins service
For best reliability and durability, the recommended network. Cummins offers the largest
maximum gross vehicle weight (GVW) for the ISX12 G service network in North America.
in line-haul applications is 80,000 lb (36,287 kg). Select Cummins-authorized technicians are
gearing for fuel economy in line-haul and regional-haul fully trained on Cummins Westport natural gas engines,
applications where the engine operates at 1400 rpm to with ready access to Genuine Cummins parts and
1500 rpm at cruise speed. For vocational applications warranty support. For questions regarding your Cummins
select gearing where engine operates at 1450 rpm to 1600 Westport engine, or for assistance in finding a repair
rpm at cruise speed. facility in the United States or Canada, call Cummins Care
at 1-800-DIESELS (1-800-343-7357).

Optimizing Performance With PowerSpec.

Cummins Westport The Natural Choice.
Cummins PowerSpec helps you find the ideal gearing
specs for engine performance or fuel economy, making Cummins Westport Inc. designs, engineers and markets
it possible to tailor the operation of Cummins Westport 6- to 12-liter spark-ignited natural gas engines for
engines to fit every customers application. PowerSpec commercial transportation applications such as trucks
can also read fault codes, and can be programmed to and buses. Our dedicated 100 percent natural gas
collect trip information for multiple drivers. PowerSpec engines are manufactured by Cummins, and are available
works on every Cummins Westport engine, from the as a factory-direct option from leading truck and bus
ISL G to the ISX12 G. manufacturers.

See cumminsengines.com/powerspec for more information. To learn more about natural gas engines for transportation,
and how natural gas can work for your fleet, visit the
Cummins Westport Natural Gas Academy online. Youll find
videos, information and resources about engines, OEM
availability, fuel systems, refueling, maintenance and more:
cumminswestport.com/natural-gas-academy
101-1750 West 75th Avenue, Vancouver, B.C., Canada V6P 6G2
Phone 604-718-8100 info@cumminswestport.com cumminswestport.com
Bulletin 4971500 Printed in U.S.A. 3/15 2015 Cummins Westport Inc.