X12 Overview Image

X12 (2018) for Motorhomes

Power 455 - 500 hp
339 - 373 kW
Torque 1550 - 1695 lb-ft
2102 - 2298 N•m


When it comes to Class A motorhomes, nothing provides more luxury and power than the Cummins X12. 

  • Up to 500 HP and 1700 lb-ft of torque 
  • Compact design for easier access to maintenance points
  • 20% stronger compression braking
  • Annual maintenance intervals

Advances to the emissions system provides exceptional thermal efficiency, minimizing regeneration and improving fuel efficiency. With the highest power-to-weight ratio of any heady-duty engine, the Cummins X12 is the ideal choice for your luxury Class A motorhome.

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

  Advertised HP (kW) @ RPM Peak Torque LB-FT (N•M) @ RPM
X12 500 500 (373) @ 1900 1695 (2298) @ 1000
X12 455 455 (339) @ 1900 1550 (2101) @ 1000
  • Cummins on Every™ Corner – Over 3,700 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.

  • 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 the Motorhome & RV section of cummins.com

Maintenance Item Interval
Oil and Filter 20,000 Miles / 12 Months
Fuel Filter 30,000 Miles / 12 Months
Overhead Adjustment 300,000 Miles
Coolant Consult OEM Manual

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