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Mechanics Corner: Tier 4 interim emissions regulations spur technology improvements

Tim O'Brien Published on 24 August 2011
Editor’s note: The first in a two-part series of articles discussing new Tier 4 emissions requirements and technology to meet them.

By now, you have probably heard about new U.S. Environmental Protection Agency’s (EPA) Tier 4 emissions requirements for off-highway equipment powered by diesel engines.

The EPA initiated the first emissions standards for off-road engines more than 13 years ago. With each new stage or tier, EPA standards have established lower allowable emissions. EPA regulations are generally consistent with European, Japanese and Canadian rules, demonstrating a cooperative international approach to this issue.



Tier 4 targets a 90 percent reduction in emissions from Tier 3 standards by 2014, which will contribute to substantially improved air quality. Key to meeting Tier 4 is reducing the main pollutants in emissions: carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HC) and particulate matter (PM). Emissions limits are particularly focused on curbing airborne NOx and PM.

According to the EPA, off-road engines are responsible for 47 percent of PM and 25 percent of nitrogen monoxide and NOx emissions from all mobile sources nationwide. NOx is produced during combustion when the engine is at its hottest.

PM consists of tiny carbon particles and other poisonous substances. PM results from incomplete fuel combustion, which most often occurs when the engine is cooler.

When inhaled repeatedly, these small particles may aggravate asthma and allergies or cause other serious health problems.

Effective January 1, 2011, engines greater than 174 horsepower (130 kW) must meet Tier 4 Interim requirements. For engines in the 75 to 174 horsepower (57 to 130 kW) range, Tier 4 Interim requirements take effect January 1, 2012. Tier 4 Final requirements take effect January 1, 2014.


Tier 4 emissions requirements apply to new equipment and are not applied retroactively to existing equipment.

We will meet these requirements in a way that continues to satisfy customers’ needs for productivity, fuel efficiency and minimal downtime. For us, meeting Tier 4 emissions requirements is part of getting the job done right. And it’s part of our commitment, as a global corporate citizen, to doing what is right for our customers and the environment.

Meeting Tier 4 requirements
As an original equipment manufacturer with a global footprint and a history of technological leadership, we benefit from the tremendous breadth and depth of our equipment design experience and research and development resources.

You can expect Tier 4 Interim and Final solutions from us that are integral to the machine, so there will be no after-market add-ons or awkward designs. For example, we are maintaining the same excellent visibility and stable weight distribution characteristics our customers expect from our equipment.

Implementing the technologies to achieve the necessary emission reductions will come with a cost. Final pricing will depend on a variety of factors, including machine re-engineering to incorporate the Tier 4 technology, but customers can expect to see prices of Tier 4-certified machines to be approximately 5 to 15 percent above those of current Tier 3 models.

In achieving Tier 4 Interim certification for the new equipment, we have taken advantage of the opportunity to introduce many important new upgrades and expanded capabilities, greatly enhancing the overall value and utility of the machines.


Two primary technology approaches have been developed to address Tier 4 requirements – selective catalytic reduction (SCR) and cooled exhaust gas recirculation (CEGR). Of our new models introduced since January 1, 2011, Case F Series wheel loaders use an SCR solution, and Case C Series excavators use a CEGR solution.

We see advantages to both technologies, and we are applying the solution that achieves the lowest operating costs, depending on each model’s engineering characteristics and application requirements. Our solutions integrate each model’s engine, hydraulic and electronic systems to achieve the most efficient and powerful performance.

In the concluding article of this two-part series on Tier 4, we will examine in more detail the SCR and CEGR technologies. In the meantime, you may wish to visit our informative Tier 4 website at .

There you will find a wealth of information from us on Tier 4 technologies, solutions, requirements, answers to frequently asked questions and links to other online resources to help you understand the issues surrounding Tier 4 compliance and certification. You also may call (866) 54-CASE6 to request a copy of our Tier 4 brochure. PD


Tim O'Brien
Marketing Manager
Case Construction Equipment