X12 (2018) For Emergency Vehicles


X12 (2018)  For Emergency Vehicles


  • Less Front Axle Weight – The X12 weighs 400 lbs to 600 lbs less than other medium-bore engines.
  • The Highest Power-To-Weight Ratio – The X12, with up to 500 hp and 1700 lb-ft of peak torque is also the lightest engine in its class.
  • Better Acceleration, Faster Warmup and Stronger Engine Braking – The proven Cummins VGT® Turbo incorporates 15 years of technological advancements.


  • Proven – Over 100,000 engines in service around the world with over 1 billion miles of real-world experience.
  • Optimized Emissions Control – Cummins Single Module™ aftertreatment has exceptional thermal efficiency, resulting in fewer regenerations, and meets OBD and GHG requirements.

Designed For The Fire Service.

  • Better Pump Control – Specific calibrations, for the best engine rpm or discharge pressure control when pumping.
  • No Derates – Regeneration or emissions related faults do not affect power output when you need it.
  • One Source for Service – Your local distributor supports both Cummins engines and Onan® generators.


Configuration Inline 6
Displacement 720 CU IN 11.8 L
Lube Oil Capacity 42 QT 39.8 L
Biodiesel Compatibility Up to B20
Engine Braking Horsepower Up to 450 HP @ 2300 RPM
Idle Speed 600-800 RPM
Governed Speed 2000 RPM
Engine Weight (Dry) 2050 LB 930 KG
Aftertreatment Weight** 173-191 LB 78-87 KG
**Depending on configuration

Product Finder Specifications

Power 455 - 500 hp / 339 - 373 kW
Torque 1700 - 1695 lb-ft / 2305 - 2298 N•m


  Advertised HP (kW) @ RPM Peak Torque LB-FT (N•M) @ RPM
X12 500 500 (373) @ 1100 1695 (2298) @ 1000
X12 455 455 (339) @ 1000 1700 (2102) @ 1000



  • Cummins on Every™ Corner – Over 3,500 authorized locations across North America, to support parts and service needs.
  • Peace of Mind – Base warranty backed by Cummins for a full 5 years/100,000 miles, whichever comes first. Up to 8 years of optional full engine coverage, including injectors.
  • Cummins Guidanz™ and INLINE™ Mini – Read real time engine data and email fault information from your smart phone to speed up the repair process.
  • QuickServe™ Online Mobile – Provides complete parts and service information based on specific ESNs.
  • Connected Diagnostics™ – Wirelessly connects Cumminspowered emergency vehicles to product experts at Cummins for immediate diagnosis of an engine system fault.
  • Easier Maintenance – The compact design of the X12, together with easy service points for scheduled maintenance increases uptime.
  • Get the Latest – Need more information about the Cummins X12 engine or Cummins Onan generators? Visit cumminsengines.com/fire-and-emergency. You can also stay up to date with quarterly articles in the First Responder newsletter at firstresponder.cumminsnewsletters.com.


Maintenance Item Hours Months
Oil and Filter 500 6
Fuel Filter 500 6

Brochures Available

Title Bulletin Number Request View  
2017 Engines And Commercial Mobile Generators Brochure For Emergency Vehicles 5410731 Request View  Download
X12 Benefits Summary Flyer 5410804 Request View  Download