Cummins ISX12G
Built: 2017 · Series: ISX12G
More machines from model year 2017
Not the right version? The data comes from vehicle registers holding many near-identical versions side by side. Photograph the data plate — we read make and type from it. Open the scanner e-mail address required
Cummins ISX12 G — the Predecessor of Today's Cummins Gas Engines – inline six-cylinder natural-gas engine of 11.9 litres, 320 to 400 hp, for heavy tractors and distribution trucks
The Cummins Westport ISX12 G is an inline six-cylinder natural-gas engine of 11.9 litres, running exclusively on natural gas as either CNG or LNG. Combustion uses Cummins Westport's stoichiometric, cooled-EGR (SEGR) technology with spark ignition; aftertreatment is a maintenance-free three-way catalyst packaged as a muffler. Depending on rating, output spans 320 to 400 hp (239–298 kW) with up to 1,450 lb-ft (1,966 N·m) of torque.
Read on 4 more paragraphs
From 2013 the ISX12 G expanded Cummins' heavy-duty on-highway natural-gas range and has since been fully superseded by the ISX12N, which meets stricter near-zero emission limits.
Applications included heavy tractors and distribution trucks, notably at Kenworth; ratings on record include ISX12G 320, 330, 350, 385 and 400.
As a stoichiometric, spark-ignited gas engine, the ISX12 G follows the Otto-cycle principle rather than a diesel's compression ignition; its design is governed by the knock limit of the homogeneous natural-gas/air mixture, so specific output per litre is naturally lower than a comparable diesel. Unlike diesel tractors, natural-gas trucks are tied to CNG or LNG filling stations and therefore suit distribution and regional haulage with planned routes rather than open long-haul work.
As the engine is no longer sold new, parts availability is the main practical concern for used units, alongside the original two-year/250,000-mile factory warranty framework as a benchmark for design intent; no further type-specific weak points are documented in the sources reviewed.
Sources: SpecCodex register, model data: Cummins ISX12G, Cummins (manufacturer)
Technical data
Engine
| Engine code | 3647; FR20288correct |
|---|---|
| Engine family | HCEXH0729XBAcorrect |
| Engine families | HCEXH0729XBAcorrect |
| Fuel | Compressed Natural Gas, Liquefied Natural Gascorrect |
| Rated output | 298.3 kW (= 400 hp)correct |
| Rated speed | 1,800 rpmcorrect |
| Maximum torque | 1,450 ft·lbfcorrect |
| Speed at max. torque | 1,200 rpmcorrect |
| Displacement | 11,900 cm³correct |
| Displacement | 11.9 lcorrect |
| Operating cycle | dieselcorrect |
| Injection | throttle-body injectioncorrect |
| Aspiration | turbochargedcorrect |
Origin and approval
| Version | 3647; FR20288correct |
|---|---|
| Built from | 2017correct |
| Built to | 2017correct |
| Model year from | 2017correct |
| Model year to | 2017correct |
| Sales region | USA certificationcorrect |
Other data
| Application | Both Tractor and Vocationalcorrect |
|---|
Frequently asked questions
How much power does the Cummins ISX12G have?
The Cummins ISX12G delivers 298 kW.
What engine does the Cummins ISX12G have?
11,900 cm³ displacement, Compressed Natural Gas, Liquefied Natural Gas.
When was the Cummins ISX12G built?
Production years: 2017.
What to check before buying
- Match the data plate against the order: frame size, mounting and rating have to agree.
- For used units, ask about winding condition and bearing play.
- Ask about parts availability for this series — the running costs hang on it.
A general list for this type of machine — no substitute for an inspection or an appraiser.
We do not sell machines. We ask the dealers who carry this model and come back with price and lead time.
Request a quote →
We ask the suppliers and come back with price and lead time.
Request spare parts →
This page carries 23 individual figures for this model. They come from 1 recorded source; every figure can be traced there. What we cannot document is not here — we leave gaps open rather than estimate them.
Missing a figure you were looking for? Report it →
Know this machine better? Have a photo, a manual, or know that a figure is wrong? Add it to the register →
Other models in this series
Sources: US EPA — engine certification data (retrieved August 2026) · How we check the data
Diesel engine in 3D section
Turn the model, look inside and click an assembly — each one is explained.
Parts for this engine (29)
Manufacturer part numbers from the official EPA documentation. No prices or availability — those come from the supplier.
| Teilenummer | Bezeichnung | Hersteller |
|---|---|---|
| 4902912 | Catalyst Temperature Sensor;Catalyst temp. sensor | Cummins |
| 4954574 | Catalyst Temperature Sensor;Catalyst temp. sensor | Cummins |
| 4921489 | Compressor Outlet Pressure Sensor;CAC Out Pressure Sensor | Cummins |
| 4954905 | Coolant Temperature Sensor;Coolant Temp Sensor;Coolant Temperature Sensor;Engine Out NOx Sensor 2;Coolant Temperature Sensor;Oil Temperature Sensor;Oil Temperature Sensor;Coolant Temperature Sensor;Coolant temp sensor | Cummins |
| 4921686 | Crankshaft Position Sensor | Cummins |
| 2897462 | ECM / Motorsteuergerät | Cummins |
| 4359433 | ECM / Motorsteuergerät | Cummins |
| 4313837 | EGR Cooler | Cummins |
| 5306676 | EGR Valve | Cummins |
| 2872277 | Camshaft Position Sensor;Engine Crankshaft;Camshaft Position Sensor;Crankshaft Position Sensor;Engine Camshaft;Engine Camshaft Position Sensor;Engine Camshaft | Cummins |
| 2872279 | Crankshaft Position Sensor;Camshaft Position Sensor;Crankshaft Position Sensor;Crankshaft Position Sensor;Camshaft Position Sensor;Camshaft Position Sensor;Engine Camshaft;Engine Crankshaft;Engine Crankshaft;Engine Crankshaft Position Sensor;Engine Crankshaft Position Sensor;Engine Crankshaft | Cummins |
| 2872858 | EGR Out Temperature Sensor;Intake Manifold Temp Sensor;EGR Out Temperature Sensor;EGR Out Temperature Sensor;Intake Manifold Temp Sensor;EGR temp sensor | Cummins |
| 4984929 | Exhaust Gas Recirculation Pressure | Cummins |
| 9999999 | Fuel Injector Pump;Fuel Injection Pump | Cummins |
| 1234567 | Fuel Injector | Cummins |
| 4921479 | Fuel Temp/Press | Cummins |
| 3929935 | Gas Mass Flow Sensor | Cummins |
| 2897508 | Humidity Sensor | Cummins |
| 4921483 | Intake Manifold Temperature | Cummins |
| 4954893 | Oxygen Sensor | Cummins |
| 5274559 | Three-Way Catalyst | Cummins |
| 4307480 | Turbine Inlet Temperature Sensor | Cummins |
| 4326884 | Turbine Inlet Temperature Sensor | Cummins |
| 3782466 | Turbocharger | Cummins |
| 3782467 | Turbocharger | Cummins |
| 3787965 | Turbocharger | Cummins |
| 3788265 | Turbocharger | Cummins |
| 5350774 | Turbocharger | Cummins |
| 5350778 | Turbocharger | Cummins |
Quelle: EPA HD Engines 2015–Present
Diese Teile anfragen