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Diesel Engines
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Cummins on-highway engines have been regulated by the U.S. Environmental Protection Agency (EPA) and similar regulatory agencies around the world for combustion emissions since the 1970s. Regulated emissions include nitrogen oxide (NOx), carbon monoxide (CO), hydrocarbons (HC) and particulate matter (PM), also known as soot.

Engines have come a long way in a relatively short time period. Today’s on-highway diesel engines emit 90 percent less PM and NOx compared to emissions from just a little more than a decade ago.

Cummins has been a leader in clean diesel technology, pioneering the design and use of integrated subsystem technology such as combustion, controls, fuel systems, filtration, air handling, and aftertreatment.

The Company’s commitment to innovation has enabled it to deliver exceptional fuel economy for the Company’s on- and off-highway customers, ultimately reducing their output of carbon dioxide (CO2), a key contributor to global warming.

The Company has also supported the development of biodiesel. All of Cummins’ engines produced today are equipped to run on a 20 percent blend of biodiesel.

Doing both the right thing for customers and the right thing for the environment is Cummins’ highest priority.


The U.S. Environmental Protection Agency has established the most stringent emissions regulations in the world, reducing both allowable NOx and PM levels by 90 percent compared to 2004. In 2010, all heavy-duty on-highway engines sold in the United States had to meet the EPA’s NOx standard (0.20 grams per brake-horsepower hour (g/bhp-hr)) and the PM standard (0.01g/bhp-hr).

Cummins was among the first companies to meet these new standards. In 2010, the Company successfully introduced the ISX15 engine for use in 18-wheel heavy-duty commercial tractor-trailers. The engine provides up to 6 percent greater fuel economy, stronger performance, faster throttle response and best-in-class drivability and reliability compared to Cummins’ previous industry leading ISX engine.

The 2010 regulations not only required near-zero NOx and PM emissions, but also the phase-in of advanced on-board diagnostic controls with additional sensors to monitor the effectiveness of emission-control systems on the engine. The on-board diagnostics alert drivers if emission-reduction devices fail and need to be repaired. In 2013, on-board diagnostics have been implemented across Cummins’ entire line of on-highway products for the United States.

Beginning in 2014, new greenhouse gas and fuel-efficiency rules will take effect for all on-highway engines in the United States. Cummins ISX15 was the first engine to achieve EPA certification (page 40) for the new standards – a full year ahead of schedule.
The engine provides up to 2 percent greater fuel economy than the 2012 model year engine, and maintains its best-in-class drivability and reliability.

The ISX15 features the Cummins XPI fuel system, the next generation of Exhaust Gas Recirculation (EGR), a Variable Geometry Turbocharger and Cummins Aftertreatment System that incorporates a Diesel Particulate Filter and Selective Catalytic Reduction (SCR) technology to reduce emissions. Each ISX15 can reduce CO2 emissions by up to 12 metric tons per year compared to a 2007 ISX engine.

In 2012, Cummins introduced the new ISX12 engine for the vocational and work-truck market, emergency vehicles and motor coach applications. The engine is designed to deliver better fuel economy, performance, reliability and durability in a compact design.

For the heavy-duty pickup truck market, the 2013 Ram heavy-duty trucks using a 6.7-liter Cummins turbo diesel and SCR aftertreatment will get at least 10 percent better fuel economy (depending on duty cycle) than a model year 2012 truck.

The Company also announced a new powertrain package for the North American heavy-duty truck market in 2013 that is expected to deliver a 3 to 6 percent fuel economy improvement, lower preventive maintenance costs, and reduce total lifecycle cost.

The new product combines an Eaton® Fuller Advantage™ Series automated transmission with new Cummins ISX15 SmartTorque2 ratings. The product will be available in the fall of 2013 for line-haul, regional haul and less-than-truckload (LTL) applications.


In only three years, the North American and European industrial markets have been faced with the challenge of transitioning to near-zero emissions by 2014. This challenged Cummins to look beyond basic engine technologies to areas such as high pressure fuel systems, advanced turbocharging, electronics and aftertreatment systems to further reduce off-highway engine emissions.

The resulting innovations not only helped to meet the latest regulations, but also led to more fuel efficient products that produce less CO2. The off-highway business has gone beyond simply reducing engine emissions and improving fuel economy by launching multiple “clean-sheet” engines, designed from the beginning without any constraints.

Since 2011, Cummins extended its off-highway power offering at each end of the horsepower spectrum, down to 49 hp with the QSF2.8 and up to 4,200 hp with the QSK95. Both of these engines were designed with advanced emissions control in mind and as minimal an impact to the customer as possible. They are equipped with aftertreatment systems that require no active regeneration to meet applicable regulations.

In April of 2013, Cummins introduced two additional engines at a major trade show in Munich, Germany, completing the Company’s full product lineup for Tier 4 Final from 49 to 675 hp. The new QSF3.8 and the QSM12 were developed from a clean-sheet design and fill very specific power densities to meet customer demands.