Maintaining a fleet of heavy vehicles isn't easy, and even something as seemingly straightforward as motor oil selection can turn into a significant purchasing decision. When you're buying lubricants for an entire fleet, small choices can drastically alter your maintenance costs. Choosing the right oils is a small but necessary part of keeping your fleet running reliably and cost-effectively.
Since most heavy equipment motors use diesel engines, your oil selection is, in part, dictated by EPA emissions standards. The EPA implemented standards for heavy off-road equipment (such as construction vehicles) in 1996. Since then, federal regulations have required progressively stricter emissions standards. The emissions regulations currently in use are known as Tier 4.
Tier 4 Emissions Standards and Motor Oil Requirements
Diesel engines consume a more significant amount of oil than their gasoline counterparts, especially in heavy-duty applications. As a result, lubrication oil can contribute a meaningful amount to the particulate output of diesel engines. Stricter regulations on diesel engine emissions mean that newer engines must use motor oils engineered to reduce emissions output.
Since manufacturers design these newer engines with higher tier motor oils in mind, using older oils will reduce performance and efficiency while producing potentially higher emissions. If you're selecting oil for your fleet equipment, always be aware of your motors' regulatory tier. For Tier 4 motors, always choose motor oil that meets the newer, more stringent standards.
CK-4 vs. CJ-4 Oil Standards
While federal tiers dictate engine emissions standards, the industry regulates oil standards. Oil standards such as CJ-4 are set by the American Petroleum Institute (API) and indicate that a particular motor oil meets specific testing and certification standards. For high-efficiency, low-emissions diesel motors, the CJ-4 standard was previously the top of the pack.
While CJ-4 is still acceptable for Tier 4 equipment, these oils should no longer be considered ideal. The newer CK-4 standard offers improvements that more modern engines rely on to achieve higher efficiency and lower emissions output. If your fleet consists primarily of Tier 4 vehicles, then transitioning to motor oil that meets these more stringent standards can offer real practical benefits.
Note that you should always consider more than just the API certification when selecting an oil. Consult with your equipment manufacturers to determine the oil standards that they recommend for optimal performance. Oil manufacturers also sometimes produce products that exceed currently available certifications so that some older CJ-4 oils may meet newer CK-4 testing requirements.
For more information, contact an industrial motor oil supplier in your area.
