Emission-Compliant Engines Update

Total fluid economy takes into account an engine’s total fluid consumption, including diesel fuel, engine oil and maybe a few unfamiliar fluids with today’s next generation of diesel engines (such as diesel exhaust fluid or DEF). Thanks to evermore stringent EPA emissions regulations called “Tiers,” diesel engines today have a whole host of new technologies and systems, making them Interim Tier 4-certified (the name of the latest round of emissions changes).  

When purchasing Interim Tier 4-certified (IT4) equipment, total fluid economy is an important factor to consider. Engines featuring new, IT4, cooled exhaust gas recirculation systems (EGR) take a diesel-only approach (no new fluids needed), while engines equipped with selective catalytic reduction systems (SCR) utilize both diesel fuel and DEF to achieve emissions compliance. Claims that engines with SCR consume less diesel fuel than cooled EGR-equipped engines must be examined closely to ensure that they account for the consumption and cost of the additional DEF fluid. While total fluid economy is a key consideration when selecting IT4-compliant equipment, owners and operators must understand the importance of evaluating not only the quantities of fluids consumed, but also the type and quality of fluids they utilize. When it comes to the quality of engine oil, diesel fuel and coolant, there are several key factors to be aware of.

Engine Oil

With the introduction of exhaust filters into many IT4 engines, the type of engine oil used can have a significant impact on the proper functioning and ash service life of these devices. Be sure to only use engine oils meeting API CJ-4 and ACEA E9 standards. These oils are refined with a lower trace metal content, which reduces ash accumulation and increases exhaust filter service life.

Diesel Fuel

The type of diesel fuel used can also affect IT4-certified engines. There are two key issues to be aware of: sulfur content and biodiesel concentration level. The use of exhaust filters on IT4 engines will require using diesel fuel with a sulfur content of less than 15 ppm (ultra low-sulfur diesel or ULSD). Using diesel fuels with higher sulfur content can damage the exhaust filter or catalyst, creating the need for an increased number of regenerations and leading to early replacement of the exhaust filter.

Some engines operate efficiently with biodiesel blends, providing owners and operators with fuel-choice flexibility. However, the increasing use of biofuels demands strict adherence to applicable fuel quality standards. Regardless of biodiesel blend level, be sure to verify with your fuel provider that the biodiesel blend meets ASTM D6751 (U.S.) standards or an equivalent specification. Biodiesel users are strongly encouraged to purchase biodiesel blends from a BQ-9000 Certified Marketer and to source from a BQ-9000 Accredited Producer, as certified by the National Biodiesel Board. Certified Marketers and Accredited Producers can be found at bq-9000.org.


Cooling systems found in IT4 engines require regular care and year-round protection. It is important to be selective with antifreeze and coolants because not all of them provide the protection needed to operate efficiently under extreme pressures and temperatures. This is especially critical for heavy-duty, off-highway applications that often endure punishing conditions and temperature extremes. Protecting your investment in new IT4-compliant equipment is a top priority any day, but it’s especially important in today’s economy. Engine oil type, diesel fuel and coolant quality have always been important, but the technologies needed to meet IT4 emissions regulations make them even more so today.

Kelly Carpenter is a customer support engineering manager at John Deere Power Systems, based in Waterloo, Iowa.

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