Emissions standards are not as intimidating as many think. Here is a current overview.

The Environmental Protection Agency (EPA) emissions regulations have dominated the news over the last couple of years, especially because Tier 3 standards for off-highway diesel engines started taking effect in January 2006. All of this can be very confusing to the end-user, but the whole concept can be boiled down into easily digestible bites. It isn’t hard to explain what the regulations mean to you, the contractor.

To understand the implications of Tier 3, it’s important to know where the emissions-reduction push began. It all started with the 1990 Clean Air Act, when the EPA proposed a tiered emission-reduction plan for off-highway engines of all sizes. The EPA’s designated Tiers indicate deadlines for engine manufacturers to adopt technologies that gradually lower engine emissions. The European Union (EU) later adopted its own emissions-reduction plan that is similar to the EPA’s Tier system.

Currently, the EPA only regulates 0.3 percent of an engine’s total product of complete combustion. The rest (99.7 percent) of engine exhaust is made up of natural elements in the air such as nitrogen, oxygen and water vapor. The two main emissions that are regulated are oxides of nitrogen (NOx) and particulate matter (PM). As diesel engines move from Tier 1 to completing Tier 4 Final, emissions will be reduced to almost nothing. More specifically, NOx will be reduced by more than 90 percent, and PM will be reduced by more than 95 percent.

Emissions in a Nutshell

Let’s look at a quick breakdown of the details. The Tier level’s effective dates are as follows for engines 37 kW to 560 kW (50 HP to 750 HP):

  • Tier 1 spanned 1996 through 1999
  • Tier 2 spanned 2001 through 2004
  • Tier 3 spans 2006 through 2008
  • Interim Tier 4 spans 2008 through 2012
  • Final Tier 4 spans 2012 through 2015

Each Tier consists of a phasing-in of horsepower ranges. So, to use Tier 3 as an example:

  • 130 kW to 560 kW (175 HP to 750 HP) engines had to be compliant with regulations by 2006.
  • 75 kW to 130 kW (100 HP to 175 HP) engine standards take effect this year.
  • 37 kW to 75 kW (50 HP to 100 HP) will have to meet Tier 3 standards by 2008.

This means that, for example, a 50-HP engine commonly used in a skid steer loader or a mini excavator has to meet Tier 3 emissions by January 2008. Regulations for engines smaller than 50 HP skip Tier 3 altogether and go straight to Interim Tier 4. The same is true for engines larger than 750 HP. Check out www.dieselnet.com for a complete emissions schedule.

Another component of emissions regulations that might be confusing to end-users is the fact that engine manufacturers often promote their Tier-compliant engines ahead of the EPA schedule. That might mean customers will see two announcements for the same engine – one for when the manufacturer announces it has demonstrated that its product is capable of meeting a specific Tier, and one for when the EPA officially certifies the engine according to the Tier timetable. Manufacturers typically go into production with its engines ahead of emissions regulations’ effective dates to facilitate the installation of the new engines into equipment.

This all means that emissions compliance varies greatly within each engine manufacturer’s line in order to satisfy the myriad needs of different end-users with diverse horsepower needs and engine requirements. Additionally, engine manufacturers have to comply with EPA and EU standards, as well as standards from countries around the world. This makes the diesel engine business even more complicated. Each engine manufacturer has to decide its strategy to satisfy the varying levels of emissions regulations worldwide.

Customer Benefits

But what does this mean for you, the contractor? If you already were familiar with the EPA regulations and Tier schedules, you’ve probably heard the obvious environmental positives. Aside from working toward cleaner air, engines meeting emissions standards also can bring with them other benefits.

“Instead of making sacrifices with our engines in order to meet Tier 3 standards, we have been able to improve engine performance and fuel economy, and those are very tangible customer benefits,” says Doug Laudick, product manager at John Deere Power Systems. “Obviously, we’re pleased that we’re improving fuel economy, especially when most customers expect manufacturers to keep levels the same. Everyone has been asking what the advantages of emissions-driven engine enhancements are. We think this is a major one.”

Some other end-user benefits that Tier 3 engines offer, Laudick says, include increased levels of power bulge, peak and low-speed torque, and transient response time.

In general, a lot of misunderstanding and anxiety have surrounded the emissions issue, and addressing these concerns head-on should demonstrate why the EPA standards are good for everyone.

Design development and verification testing is a long, evolutionary process, and typically engine manufacturers are developing and testing more than one solution. As a result, final information on lower-horsepower Tier 3 engines with emissions deadlines in the future is less detailed, and the information is even less firm for Interim and Final Tier 4 solutions. That said, many of the technologies applied to engines 175 HP and above will be applied to Tier 3 engines less than 175 HP.

Job Quality, Engine Quality

Unfortunately, the market sometimes is too focused on the complex nature of the EPA Tiers and effective regulation dates, and customers often engage in the negative discussion that commonly arises when equipment improvements are involved. But, in the end, it’s critical to realize that the emissions regulations have a great deal to do with not only a better environment, but also the increased performance and improved fuel efficiency that these new engine technologies can possibly provide.

When you combine all of this with the environmental benefits, it’s all significantly positive for this generation and generations to come.