Recommended Oil for Yanmar Tractors

Updated July 20, 2017

Powered by diesel engines produced by Yanmar American Corporation, Yanmar tractors are widespread across American farming communities. As with any combustion engine, oil is essential for the good operation and long-life of Yanmar engines. Neglecting oil changes or selecting the wrong oil leads to multiple problems and breakdowns. With such a wide range of oils on the market, choosing the right oil for a Yanmar engine can prove daunting.

Oil Importance

Unlike gasoline engines that use oil only for lubrication, diesel engines also require oil for engine cooling and cleaning carbon deposits from the pistons. Low or no oil pressure leads to engine lock-up, resulting in an engine rebuild. Preventing oil pressure problems requires regular checking and changing of oil. For Yanmar diesel-powered tractors, oil needs changing every 100 hours or every 3,000 miles; however, the type of oil chosen may affect the frequency of oil changes.

Types and Viscosity

Oil comes in two basic types: mineral oils, refined from crude oil, and chemical-based synthetic oils, which also contain some quantity of mineral oil. Most mineral oil is good enough for a diesel engine like a Yanmar, but requires more frequent changing than synthetic oil.

Measured at different temperatures, engine oil viscosity ratings include 5W-30, 10W-40 and 15W-50. The number before the W indicates viscosity in a cold engine; the number after is for a hot engine. The lower the numbers, the better protection on cold starts and lengthy usage.

Oil Categories

For a Yanmar tractor, a more important consideration than the viscosity and type of oil is using oil designed for diesel engines. Oil categories vary depending on the age and style of the engine. Common categories suitable for a Yanmar diesel engine include CG, developed for low-emission, high-speed, four-stroke diesel engines; CF, commonly used for off-road and heavy-duty diesel engines; and CE for heavy-duty diesel engines with turbochargers. Some of these categories have numbers attached to the rating that indicate higher performance levels.

Changing Oil

Aside from the type and category of oil chosen, a higher frequency of oil changes provides increased reliability of an engine. Changing oil on a Yanmar engine involves removing the drain plug under the engine, allowing the oil to drain into an oil pan; changing the oil filter and filter gasket; cleaning the filter housing with a clean film of oil; replacing the drain plug and refilling with clean oil.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Richard N. Williams has been a journalist for over a decade. Graduating with a bachelor's degree in journalism for the University of Staffordshire in the U.K., he has worked in various forms of journalism from news and current affairs for the national press, to technical authoring and business writing.