With winter approaching in much of the country, operators of diesel-powered mining and construction equipment should be thinking about whether they have the right lubricants for their operating conditions. Speaking recently on Equipment World magazine’s weekly webcast, “The Dirt,” Chevron Lubricants engineer Shawn Whitacre answered questions about how to select engine oils as the operating environment changes.

Viscosity grade, based on the Society of Automotive Engineers or SAE classification system, is the first and foremost consideration when selecting an engine oil for any operating conditions. The first number in the classification is an indicator of the oil’s ability to perform in low temperatures. (The “W” that accompanies this number stands for “winter,” appropriately.) The second number represents the fluidity of the oil in normal operating temperatures.  If you’re going to be operating in low temperatures for an extended period of time, or if you’re routinely shutting equipment down at night and want to be sure it starts up quickly in the morning, you’ll want a lower-viscosity oil, such as a 10W or 5W.

In addition to the viscosity grade, fleet maintenance managers should also be aware of the American Petroleum Institute or API oil categories. Most oils for diesel applications fall into the C category (for example, CK-4), while oils for gasoline engines are in the S category. However, for construction equipment, dual classification S and C oils, sometimes called “universal” oils, are available. These may be suitable for smaller sites that have a mix of gas- and diesel-powered equipment, where operators are trying to use as few lubricant products as possible.

In parts of the country that experience wide temperature variations from summer to winter, operators may want to consider synthetic oils. The chief attribute of synthetics is their ability to maintain fluidity across a wide temperature range. Synthetic blends, formulated from a combination of synthetic and mineral base oil stocks, are another option that offers lower viscosity properties at a lower price than a full synthetic.

Shawn also discussed a problem common to newer Tier IV engines that have EPA-mandated exhaust aftertreatment systems: the clogging of diesel particulate filters (DPFs) from non-combustible ash in the exhaust stream. Most of that unburned ash is a byproduct of metallic additive components in the engine oil. It can be a costly problem on a construction site or in mining operations if a piece of equipment has to be taken out of service for DPF cleaning or repairs, especially if the site is far from maintenance facilities. Downtime for DPF maintenance can be minimized – and in some cases, completely eliminated – through the use of an ultra-low ash oil such as Delo® 600 ADF, which contains 60% less sulfated ash than a comparable CK-4 oil.

Shawn’s wide-ranging conversation with “The Dirt” host Bryan Furnace also touched on the longer drain intervals possible with newer, higher-quality oils. Ultimately, it pays to stay up to date on OEM recommendations rather than fall back on old oil change rules of thumb. You may find you can extend drains to as much as 500 or even 1,000 hours for certain types of equipment and duty cycles.

This is the right time of year to be thinking about seasonal changes, especially as construction activity starts picking up after a couple of quiet years. For more tips on getting the optimal protection and performance from your lubricants, watch the full interview.