What You Need to Know About Tier 4 Equipment

The transition to Tier 4 engine technology will continue through January 2015. Understanding the implications of this transition and what to expect as new machines enter the market will help you determine what machine will best fit your needs.

Tier 4 engines such as the one pictured above from Perkins Engine often includes after treatment devices such as diesel oxidation catalysts (DOC) and diesel particulate filter (DPF).
Tier 4 engines such as the one pictured above from Perkins Engine often includes after treatment devices such as diesel oxidation catalysts (DOC) and diesel particulate filter (DPF).

Tier 4 is the government mandated reduction in harmful exhaust gases for diesel powered equipment. Tier 4 is currently the law of the land. It is no longer avoidable if you want to purchase new equipment. But there are many unanswered questions that make the decision to purchase more difficult than in the past. In order to understand the implication of Tier 4 regulations, it’s helpful to understand how diesel emissions regulations began.

The U.S. Environmental Protection Agency is a product of the Clean Air Act, which requires the agency to monitor air quality and eliminate threats to human health.
Two major components of diesel exhaust lead to the EPA's regulating diesel emissions. Oxides of nitrogen (NOx) combine with ground-level ozone and other pollutants to form smog, and particulate matter (PM), or soot, has been found to be a serious lung irritant and potential carcinogen.

EPA chose to regulate diesel engine emissions at manufacturing, requiring new engines be certified to restricted levels of NOx and PM. However, when the regulations were being crafted, there wasn't a clear technology path to achieve the final target level of emissions. So the regulation phased in gradually decreasing allowable levels of NOx and PM called "Tiers" starting in 1996 and completing in 2015.

Considering the broad range of diesel engine sizes and acceptable price increases for a given size engine, the Tiers were prescribed for specific horsepower ranges to spread out the development workload, mange the cost for regulated manufacturers and to make an economic case for each set of engines. The result is a matrix of dates, horsepower ranges, and emissions levels spreading back to 1996.

The implications of Tier 4
Certain factors will drive demand for Tier 4 equipment, such as bid specifications and permits requiring diesel emissions reductions. Tier 4 equipment may be required or give you an advantage when bidding government jobs or work located in EPA-designated non-attainment zones (most major urban areas). A non-attainment zone is a specific region that is out of compliance with the Clean Air Act through the proliferation of one or more defined pollutants.

Although purchasing new equipment with the latest certified engine usually carries the highest immediate capital expenditure, this option ensures the equipment is compliant with the latest emissions standards, and is sometimes the best long-term financial decision for the equipment owner.

But questions do remain about performance, reliability, operating costs, maintenance and residual values. The answers to many of these questions may remain in flux until a core number of machines enter the market.

Understand your options
There are no universal solutions for Tier 4. The technologies used will depend on the size of the diesel engine and the technology approach of the particular manufacturer. For Tier 4 Final, you will really need to study available diesel engine technologies to determine which best fits your application. No single technology enables an engine to meet the stringent emissions standards. Rather, it is a complex combination of proven strategies such as in-cylinder combustion optimization, turbocharging strategies, exhaust gas recirculation (EGR) and high-pressure fuel injection with multiple events per cycle.

Advanced technologies aren't always needed for smaller engines that must conform to slightly less stringent standards. In the lower horsepower range, the solutions are, for the most part, less complicated.

You can expect price increases anywhere from 8 percent to 20 percent depending on the type of equipment. This cost increase will be partially offset by fuel economy improvements up to 5 percent.

Equipment will continue the technology transition through January 2015. Keep in mind that Tier 4 Final implementation dates are staggered.

  • For engines from 175 to less than 750 hp, the Tier 4 Final regulations took effect on January 1, 2014.
  • For engines from 49 to less than 75 hp, it took effect on January 1, 2013.
  • For engines from 75 to less than 175 hp, Tier 4 Final is required by January 1, 2015.
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