Oil is incredibly important to keep your engine lubed up and running. Particularly in two-stroke mower engines, where oil and fuel are combined, having the right oil can mean the difference between getting your lawn mowed or having to take your mower in for repairs. So what oils are recommended for use in lawn mowers, and why?
Brand Names Don’t Matter
Your lawn mower manual will most certainly recommend that you use their brand of oil, but it really doesn’t matter in the long run – as long as you are using an oil that is specifically formulated for use in a lawn mower, you’re fine. The same goes for name-brand versus generic oil – in fact, the generic oils will often be your best bet, providing the same quality for a lower price.
Two-Stroke Oil versus Lawn Mower Oil versus Automotive Oil
If your lawn mower is a two-stroke engine, make sure to use two-stroke oil in combination with the gasoline as recommended by the manufacturer. Do not use regular lawn mower oil in two-stroke engines, or the other way around. Do not use automotive oil in your lawn mower or in a two-stroke engine – the additives and detergents in the automotive oil are not healthy for your lawn mower. Look for oils labelled as acceptable for service SF, SG, SH, or SJ.
Choose the Right Viscosity
The appropriate viscosity is what will help your engine be lubricated thoroughly, even though the temperature may fluctuate. One viscosity doesn’t perform the same as another, and so there are two common viscosities for use in lawn mower engines. The first, SAE 30, is great for mowing during the regular mowing seasons, but will often result in hard starting when the temperatures drop below 40 degrees Fahrenheit.
The second viscosity, 10W-30, is better in cold weather, but will often see increased fuel consumption and burn-off in weather above 80 degrees Fahrenheit. Choose the viscosity that is most appropriate for your surroundings – if you live in an area where you may still need to mow into the cold months, this second viscosity may be your best choice.
There are plenty of bottles of oil additives on the shelves of big box stores and automotive warehouse, but don’t be tempted to add them to your lawn mower. These additives are only helpful in large engines, they will only harm small lawn mower engines.
We hope that this clears up some of the mystery when it comes to choosing oil, and that it helps you out the next time you’re stuck replacing your oil.