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How Does This Affect Me?
 From an equipment owner’s or operator’s perspective, sometimes it’s difficult to bridge the gap between how emission regulations affect and change the final product of an engine for construction equipment. These diesel power plants will be much cleaner when it comes to expelling environmental pollution, which is a good thing.
But these newer, better, cleaner-burning engines will most likely cost more to purchase and will have extra maintenance, though manufacturers are trying to offset some of those costs with extra goodies.
“In broad comparison terms to Tier 3, clearly the introduction of Tier 4 will bring unavoidable cost increases with the addition of exhaust after-treatment and enhanced engine technology. In the end, Tier 4 equipment pricing will be determined by the OEM,” says Schroer. “However, with up to 5 percent fuel-efficiency saving from Cummins Tier 4 engines, depending on rating and duty cycle, this will reduce the cost of operation to help offset equipment cost increases for Tier 4.”
Future engine designs will not just include an upgrade in engines, but will require an evolution of some fuel systems and cooling systems needed to effectively offset the high temperatures that are required to burn off NOx exhaust. Redesigning these cooling systems will require larger fans and more openings to cool engines, which could mean machines running louder and being less fuel efficient.
For the most part, day-to-day maintenance between Tier 3 and Tier 4 engines will remain unchanged, say most manufacturers — just a few extras. Cummins Tier 4 engines will incorporate a coalescing crankcase filter to meet EPA regulations, which requires the elimination of crankcase emissions, also known as blow-by gasses. A quick, simple replacement element change is required at 2,500-hour intervals for the filter.
John Deere noted that its maintenance of new engines will be comparable to its current product, but there are some additions — like cleaning out the ash from a DPF unit — a diesel particulate filter that traps soot in the exhaust.
MTU Detroit Diesel noted that refilling of urea will be needed and can be done at the same time the equipment is refueled. “The use of SCR actually reduces fuel consumption, so the total consumption of fluids — fuel and urea combined — remains about the same,” says Mangum.
Non-road diesel fuel will also be changing. From Tier 1 through 3, the sulfur content in non-road diesel fuels was not limited by environmental regulations. But to enable sulfur-sensitive control technologies in Tier 4 engines — such as catalytic particulate filters and NOx adsorbers — the EPA mandated reductions in sulfur content in non-road diesel fuels.
“In meeting the 2011 emissions requirements, diesel fuel is a critical part of the solution. Ultra-low sulfur diesel [ULSD] is necessary for most after-treatment technologies as high levels of sulfur will be detrimental to the after-treatment and may not be emissions-compliant due to the increased production of sulfates,” Schroer says.
Keeping all of these technologies in mind, equipment managers must remember that Tier 4 changes are not by types of machines, but instead by the horsepower bands. Smaller engines, 74 hp and below, already have to meet Interim Tier 4 regulations, which went into effect in January 2008. For the 75- to 174-hp power band, Tier 4 Interim will take effect in January 2012.
NOTE: Manufacturers are given the option to move to Interim Tier 4 in 2008 or opt to skip Interim Tier 4 and go straight to Final Tier 4 in 2012 , which is a year earlier than if the manufacturer opted to go to Interim Tier 4 in 2008. If the manufacturer met the Interim Tier 4 regulations in 2008, they move to Final Tier 4 in 2013.
Keith Gribbins is managing editor of Utility Contractor.
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