As of 2015, the strictest emissions standards ever for off-road diesel engines of all horsepower classes became official. They were built up to gradually; Tier 1 regulations were first introduced in the mid 1990s, and Tier 4 Interim standards were seen starting in 2008 to 2011 for engines of differing horsepower. Now, the Tier 4 Final requirements (as they’re known in America) are here—and they’ve also been applied across much of Europe, Japan, and elsewhere.
Heavy equipment manufacturers have outfitted their diesel engines with various types of in-cylinder or exhaust after-treatment components to meet these new emissions standards. These latest EPA engine standards have successfully driven down emissions and lowered the carbon footprint of the construction industry. Their main goal was to significantly reduce emissions of two major atmospheric pollutants: particulate matter (soot and other unburned hydrocarbons) and nitrogen oxides (a key component of smog).
However, they’ve also increased engine production costs, and therefore machine costs, too. But innovative heavy equipment manufacturers like CASE have taken the opportunity to design Tier 4 Final engines that meet requirements while delivering higher power and performance and up to 5% greater fuel efficiency over Tier 3 that offsets additional purchasing costs over time.
To give you a better idea of what’s happened in light of current requirements, we’ve outlined major Tier 4 engine changes below (though some listed items are common but not necessarily used in every engine).
Tier 4 Final Engines:
- Come with a factory-installed diesel oxidation catalyst (DOC) and/or diesel particulate filter (DPF)
- Contain a selective catalytic reduction (SCR) unit to cut drastically cut nitrogen oxides
- Have an open crankcase ventilation (OCV) filter that captures and controls crankcase emissions
- Use ultra low sulfur diesel (ULSD) and CJ-4 oil that reduces ash deposit
- Run recirculated exhaust gas through a cooler, and typically have larger cooling systems
- Have multiple fuel injection capabilities and advanced fuel injection systems
- Include new engine control modules that more effectively monitor and control engine operating parameters
- Achieve optimum combustion with improved combustion bowl geometry
- Contain high-durability ferrous cast ductile (FCD) pistons
- Have a variable geometry turbocharger for better airflow control at all operating speeds and loads
- Necessitate some additional switches and dash lights operators must become familiar with
Remember Scheduled Maintenance
The advanced technologies of Tier 4 Final still depend on scheduled maintenance to continue with optimal performance. Skipping service, cleanings, or component replacement interferes with the engine’s proper emissions control, power, and efficiency.
Missing regular maintenance also jeopardizes the health of engine parts, the entire engine, and even the machine as a whole. This creates the risk of machines going down and needing considerably more time-consuming, expensive repairs, part replacements, and even equipment replacement.
Please remember to follow the manufacturer-recommended maintenance schedule.