Nitrogen oxides (NOx) and particulate matter (PM) are undeniable contributors to the formation of ground-level ozone and the presence of harmful airborne pollutants. Since the Environmental Protection Agency has concluded that the effects of long-term diesel engine exhaust fumes pose a serious threat to human health, it’s difficult for a detached observer to feel too upset about the stricter regulations being put into place to help reduce emissions.

But for the manufacturers and other owners of nonroad diesel engine applications that must take into account the new rules, frustrations can easily begin to pile up. Their operations are often already heavily streamlined and rely on each piece of the puzzle fitting precisely to achieve maximum efficiency. Adding a new piece to the puzzle (or making one piece slightly larger, say, or more difficult to locate) can threaten far more than just headaches. It can briefly derail an operation or shut down a jobsite.

So, what are the issues? What is it about the implementation of final Tier 4 standards that’s keeping people up at night? Here are some of the problems we most frequently encounter.

Base Constraints

The extra components required by most emission-reduction strategies make for a larger engine. But the space in which the engine must be mounted rarely grows alongside it. More machinery is destined for the same sized space, and that can be a problem. This fact has the potential to affect parts of the manufacturing process that seemingly have nothing to do with the power solution. In the absence of a clever engineering solution, it can prompt huge changes within an organization.


There are a number of strategies diesel engine manufacturers are pursuing to reduce emissions from their products. Unfortunately, some of them involve a practice known as regeneration, which means that the engine temporarily operates at a higher-than-normal temperature in order to burn off excess PM. What this often means for customers is downtime, since the engine can’t be operated normally during this period. Not all Tier 4 engines make use of this strategy, but it is something for customers to consider as they shop for their final Tier 4 solution before the upcoming deadline.


Many manufacturers had grown comfortable with their buying process. It was easy. Lay out the application and horsepower requirements and receive a product that’s dropped into the application and ready to go. Here again, final Tier 4 regulations are changing the game. Often, the price now quoted by manufacturers will not include key components necessary for satisfying the emissions requirements, or the components will come assembled.

Solving the Problem 

The deadline for the implementation of final Tier 4 standards is coming. By the end of the year, those affected will need to have a solution in place or face the possibility of penalties and fines. So it’s important that nonroad diesel engine owners are able to get the help they need to make the right decision regarding their application.

Here are a couple of strategies for making sure the headaches are kept to a minimum. First, verify that your application does indeed fall under the umbrella of the final Tier 4 regulations. It may seem obvious, but emergency energy sources, legacy equipment and natural gas applications are common exceptions that are often overlooked.

Next, make sure that the price you’re quoted includes all the components necessary for satisfying the criteria and whether or not they come already assembled. Buying on low-bid alone becomes more hazardous when these conditions are not taken for granted.

Finally, and perhaps most importantly, insist on a qualified engineering and support staff. Their expertise will be useful far beyond simply helping you to pinpoint the right product. They’ll be able to assist with any issues concerning base constraints and help to find alternatives to the regeneration strategy.

While preserving air quality may present some short-term inconveniences, finding the right engine manufacturer can help to overcome all of them. Business will be back to normal soon.