There are still some drivers who check their oil levels every time they gas up, but most mowers of lawns tend to ignore the oil needs of their gas-powered lawn mowers. As a general rule, the essential lubricants in your lawn mower should be refreshed after every 30 to 50 hours of operation and at a minimum, once every mowing season.
Most gas-powered lawn mowers sold and in use today have 4-stroke engines that accept engine oil in much the same way as cars. You check the dipstick and if it reads low you add more, but not too much. Most mowers have an oil capacity of around 16 ounces. Drain the oil as needed (refer to your owner’s manual). Then add the new oil. You’ll have to dispose of the old oil at a disposal site.
Lawn Mower Oil Type
So what kind of oil should you use? If you have an older two-stroke mower you probably know the drill already. The oil is added to the gas every time you fuel up, usually at an oil-to-gas ratio of 32 to 50 to 1. Because two-stroke engines are very loud and heavy polluters, you won’t find many of them around anymore. For a four-stroke mower engine, where the oil is poured into the crankcase as with a car, you can purchase special small-engine oil in a variety of weights, depending largely on the operating temperature in which you are mowing. Small engine oil is recommended by lawn mower manufactures because it has detergents that benefit your machine. But, you can certainly use regular automotive motor oil if it is more convenient. Do check your mower owner’s manual for recommendations.
Here are some basic guidelines for choosing oil products for your lawn mower, whether riding or walk-behind. Look for oil classified as For Service: “SF,” “SG,” “SH,” or “SJ.” Synthetic oils may be used.
SAE 30: A safe bet, especially in warmer climates
SAE 10W-30: Also a good general product; good for cold-weather starting
5W-30: Preferred for cold weather starting