ISL9 for Motorhome (EPA 2010)

Power 400 - 450 hp
298 - 336 kW
Torque 1250 - 1250 lb-ft
1695 - 1695 N•m
Certification EPA 2010


Clearly Better In Every Way.

The bigger and more luxurious the motorhome, the more reason you have to spec a Cummins diesel.  The ISL9 delivers everything you expect - power, reliability, efficiency and durability - every mile of every trip.  With a peak torque of 1250 lb-ft (1695 N•m), it has the power to climb steep grades with ease.  Even while towing a vehicle.

Reliability of the ISL9 is enhanced with our proprietary XPI fuel system, designed and manufactured by Cummins with fewer moving parts than competitive units have.  The XPI fuel system is capable of the highest injection pressures in the industry.  This, together with a more robust ECM, enables multiple injection events for cleaner, quieter and more complete combustion.  The XPI is the same fuel system long-haul truckers use in their Cummins ISX15 engines - so you know it's got to be dependable.

Maintenance has been kept to an absolute minimum, with the only addition being a Diesel Exhaust Fluid (DEF) filter.  At Cummins, we know that the less time and money you spend in the service bay, the more you'll have left for fun.

And that’s just a few of the features the ISL9 has to offer to help both your vehicles, and your business, run smoother.  These engines are designed to keep your maintenance to a minimum and your performance productivity in overdrive.

All backed by the best customer support in the business.

Plus, you get exclusive Cummins programs like Coach Care™ to meet your service needs as you travel across North America in your motorhome. All backed by the most extensive customer support network in North America.

For Cummins-branded merchandise, electronic tools, literature and more, visit our PowerStore web site.

Advertised Horsepower  450/400 hp  336/298 kW 
Peak Torque  1250 lb-ft  1695 N•m 
Governed Speed  2200 rpm  
Clutch Engagement Torque  550 lb-ft  746 N•m 
Number of Cylinders 
Oil System Capacity  7.3 U.S. gallons  27.6 liters 
System Weight  1,895 lb  859 kg 
Engine (Dry)  1,695 lb  769 kg 
 Aftertreatment System* 200 lb  90 kg 

*Increase over standard muffler and does not include chassis OEM-supplied components

Engine Model  Advertised Horsepower (kW)  Peak Torque lb-ft (N•m) @ rpm  Governed Speed 
ISL9 450  450 (336)  1250 (1695) @ 1400  2200 
ISL9 400  400 (298)  1250 (1695) @ 1400  2200 

XPI Fuel System - Delivers a precise quantity of fuel at ultra-high pressures.  This, together with more robust electronic engine controls, enables multiple injection events per cycle.

Heavy Duty Design - Rugged features include replaceable wet liners, roller followers, by-pass oil filtration and targeted piston cooling for longer service in the toughest work environments.

VGT™ Turbocharger - Enhanced response and control with electric actuation for infinite adjustment, providing exact boost at any rpm. Sliding-nozzle design increases reliability and durability.

Cooled EGR - Next-generation system lowers combustion temperatures for reduced emissions and optimized fuel economy.

Fully Integrated Electronic Controls - A single, higher-capacity Electronic Control Module (ECM) controls everything from air intake to exhaust aftertreatment for peak performance and near-zero emissions.

Cummins Aftertreatment System - The proven Cummins Particulate Filter reduces particulate matter by over 90%. In 2010 it is combined with Cummins Selective Catalytic Reduction (SCR) to meet emission standards while maintaining best-in-class performance, reliability and durability.

Maintenance Item  Miles / Kilometers  Hours  Months 
Oil and Filter*  20,000 mi
32,000 km 
500  12
Primary Fuel Filter**  20,000 mi
32,000 km 
500  12 
Secondary Fuel Filter  40,000 mi
64,000 km 
1,000  12 
Coolant Filter  None*** None***  None*** 
Overhead Adjustment  150,000 mi
241,500 km 
Standard Coolant Change  80,000 mi
128,000 km 
2,000  24 
Coalescing Filter  Every 3rd to 4th Oil Change Interval 
DEF Filter  200,000 mi (320,000 km) 
Particulate Filter  200,000 - 400,000 mi (320,000 - 640,000 km) 

*Assuming normal duty cycle.
**OEM supplied, intervals may vary.
***If engine is equipped with an optional coolant filter, it will need to be replaced on the same intervals as the oil filter.  Regardless if the engine is or is not equipped with a coolant filter, SCA/DCA additive levels must be checked according to the interval listed in the Owner's Manual.
****Extended coolant and drain/fill/flush intervals may be followed when certain requirements are met.  For more information on these requirements, refer to the Cummins Coolant Requirements and Maintenance Service Bulletin 3666132.

For complete maintenance information, please consult your Owner's Manual or Operations and Maintenance Manual.

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