QSB4.5 for Construction (Tier 4 Interim)

Power 110 - 168 hp
82 - 125 kW
Torque 347 - 460 lb-ft
470 - 624 N•m
Certification Tier 4 Interim / Stage IIIB

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Cummins next generation 4-cylinder QSB4.5 engine will meet U.S. EPA Tier 4 Interim and EU Stage IIIB off-highway low emission regulations in 2012 with our proven 4.5-liter engine platform and a fully integrated system from air-intake to exhaust aftertreatment.

The QSB4.5 achieves these very low emission standards by using our proven cooled Exhaust Gas Recirculation (EGR) and Cummins Particulate Aftertreatment.  Both systems have been specifically developed to maintain its compact design ensuring the most space efficient installation and premium performance for every application. 

Cummins cooled EGR coupled with our High Pressure Common Rail (HPCR) fuel system provides a cleaner and more efficient combustion resulting in up to 5 percent better fuel efficiency* compared to the Tier 3 / Stage IIIA engine.  With better fuel efficiency and ratings that extend from 110 to 163 hp (82 to 126 kW), the QSB4.5 provides the lowest cost of ownership while retaining a power band that offers improved torque delivery.

Tier 4 Interim and Stage IIIB 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.  The new Variable Flow Turbocharger with electronic control managing the cooled EGR flow across the entire rpm range.  The engine also incorporates a crankcase ventilation system with a highly-efficient coalescing filter for cleaner engine operating conditions.  Cummins combines full-authority Quantum System electronic controls, managing all components for a completely integrated system with the impressive reliability and durability and long maintenance intervals you expect from the industry’s Tier 4 technology leader.

With the next generation QSB4.5, you get premium performance, reduced maintenance and exceptional global customer support with the same reliability and dependability our customers have come to expect from our Tier 3 platform.

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 duty cycle and installation optimization.

Engine Type  In-Line, 4-Cylinder 
Displacement  4.5 L* (275 cu in) 
Advertised Horsepower  110-168 hp (82-126 kW)
Peak Torque  347-460 lb-ft (471-624 N•m) 
Aspiration  Turbocharged and Charge Air Cooled 


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

Variable Flow Turbocharger – Electronic controlled for enhanced air management.

Full-Authority Electronic Controls - Higher microprocessor capacity and speed for optimum control of the engine and aftertreatment.

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

Cummins Particulate Aftertreatment System - Fully integrated for uncompromising performance and reliability.  Removes over 90% of particulate matter and is specifically developed to withstand severe shock loads and vibrations typical of industrial 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.

HPCR Fuel System - Delivers a precise mixture of fuel and air at a constant pressure, regardless of engine rpm.  This flexibility in injection timing allows multiple injection events per cycle.

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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