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 1695 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 1550 - 1695 lb-ft / 2102 - 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 1550 (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
2018 X12 For Emergency Vehicles Flyer 5410730 Request View  Download
X12 Benefits Summary Flyer 5410804 Request View  Download