What EPA Tier 4 means to​ Manufacturers

Compliance is mandatory

Compliance with EPA Tier 4, or any other Federal/State regulatory requirements, is not optional. All manufacturers must comply if they wish to continue to sell diesel powered products in this horsepower/performance range in the future.

While Tier 4 may seem "new" to many in our business, The Toro Company has been working with our engine suppliers over the past decade to successfully comply with each Tier of the emission regulations. Since the compliant engines to meet progressively higher emission standards were more easily interchangeable in the past, much of the burden to implement the required changes fell on engine manufacturers. Going forward, however, the incorporation of new Tier 4 compliant diesel engines into Turf equipment requires significant equipment redesign because the level of emission reductions mandated in this stage will require more sophisticated fuel injection/combustion systems and exhaust after treatment systems.

Exhaust After-treatment for EPA Tier 4 Solutions In addition to more sophisticated engine electronics, the exhaust after-treatment is key to achieving EPA Tier 4 compliance. Key elements of the exhaust after-treatment systems include Diesel Oxidation Catalysts (DOCs) and Diesel Particulate Filters (DPFs). The process of removing particulate matter and NOx from the exhaust starts when the exhaust reacts with a special catalyst to transform a portion of the particulate matter into harmless substances such as water and carbon dioxide. The after-treatment process then pushes the remaining particulate matter into a Diesel Particulate Filter. This filter uses a special ceramic wall flow filtration process that further separates particles from the exhaust. Finally, the particulate material that is collected in the DPF is cleaned and purged via a high temperature regeneration process. The "burn-off" of material during this process helps maintain the efficiency and efficacy of the filtering process. This is called DPF Regeneration.

Each of the new diesel engine/exhaust systems:

1. require more sophisticated electronics [to monitor and control emissions]
2. are physically larger in size, and
3. have new and more expensive components [particularly in the exhaust after treatment area]

The above changes to integrate Tier 4 compliant diesel engines into current turf equipment models necessitate significant redesign of existing equipment/models. Examples include: retooled engine compartment housings, modifications to chassis frames, and re-engineered cooling systems to manage higher temperature exhaust, to name a few. It is estimated that over a third of the parts for a given model may need to be​ reworked, replaced or otherwise re-engineered! As such, existing models were simply not "retrofit" capable. Toro, alone, produces over twenty diesel powered models in the 25 to 74 horsepower range that will need to be addressed.

The obvious message, which no manufacturer wants to convey, is that the design, manufacturing and component costs – to deliver Tier 4 compliant diesel powered product will increase significantly on machines manufactured in 2013. Cost reductions, while always a high priority in product redesigns, will not be sufficient to offset cost increases.

What are the alternatives?

Other potential options to deliver turf equipment solutions that meet the Tier 4 regulations could include:

1. Utilization of under 25 hp diesel solutions
1. In some applications, the reduced power may produce acceptable performance
2. In other higher hp applications, electric hybrid technology is evolving which could supplement the lower hp engine during short or infrequent peak loads
2. Utilization of compliant gasoline powered engines. These solutions are generally not preferred by customers, and may have additional expenses relative to current diesel solutions.
3. Delay Tier 4 compliant product introduction. The federal regulation provides for the short-term use of "credits". In some instances, state governments are getting involved and limiting the use, or timeline for the use of credits. Any way you look at it, however, the use of credits is only a temporary solution. Eventually, all new equipment in the 25 to 74 hp and above categories must be compliant.