QSX11.9 for Construction (Tier 4 Interim)

Power 350 - 500 hp
261 - 373 kW
Certification Tier 4 Interim / Stage IIIB

Select an Application


The QSX11.9 is a clean-sheet design that incorporates Cummins proven technology enablers to meet EPA Tier 4 Interim and EU Stage IIIB low emissions standard in 2011. The QSX11.9 will achieve up to 5 percent better fuel efficiency*, lowering your cost of operation and improving your bottom line. Ratings range from 300-500 hp (224-372 kW). 

The QSX11.9 achieves these very low emission levels by using our proven cooled Exhaust Gas Recirculation (EGR) and Cummins Particulate Filter.  Both systems have been specifically developed for industrial applications delivering premium performance and durability you can depend on.

The Tier 4 Interim and Stage IIIB 11.9-liter engine incorporates Cummins Xtra-High Pressure Injection (XPI) fuel system enabling very high fuel injection pressure across all engine rpm speeds, providing cleaner combustion and improved engine response.  Together, the fuel system and Cummins Variable Geometry Turbo (VGT™) provide optimal performance with a precise match of engine rpm and load demands.

Additional performance-enhancing features include Cummins Direct Flow air filtration system providing a 35 percent smaller installation profile than radial air filters, plus improved filtration efficiency and a crankcase ventilation system with a highly-efficient coalescing filter.  Cummins Electronic Control Module manages all components for a completely integrated system providing the impressive reliability and durability and long maintenance intervals you expect from the world’s Tier 4 technology leader. 

All backed by the best customer support in the business.

Want to know what up to 5 percent better fuel efficiency will mean for your bottom line?  Visit the Fuel Duel page to find out.

*Depending on rating and installation optimization.


Engine Type  In-Line, 6-Cylinder 
Displacement  11.9 L* (726.2 cu in) 
Advertised Horsepower  350 – 500 hp (261-372 kW) 

*L = Liters/Litres

Direct Flow Air Filtration System - Specifically developed for Tier 4 platforms to provide a smaller, more flexible installation package and higher air filtration efficiency. 

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.

Variable Geometry Turbocharger (VGT™) - Enhanced response and control with electric actuation for an infinite adjustment, providing exact boost across the operating range. Sliding-nozzle design increases reliability, durability.

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

Cooled Exhaust Gas Recirculation - Lowers combustion temperatures for reduced emissions and optimized fuel efficiency.

Cummins Particulate Filter - Fully integrated for uncompromising performance, reliability.  Removes over 90% of particulate matter and is specifically developed to withstand severe shock loads and vibrations typical of off-highway applications.

Crankcase Ventilation System – Prevents crankcase emissions escaping from the engine with a highly-efficient coalescing filter.  Also, eliminates oil mist and tiny oil droplets to maintain clean engine operating conditions.

Lowest Cost Of Operation - Reduced maintenance, long service intervals and the best fuel efficiency of any engine in its class add up to superior lifetime value.

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