What oil should you use for a small lawnmower?
Look in the owners manual if you have it and see what the rating on the oil should be. I think most air cooled engines require a SG or SJ rating but I’m not sure. Air cooled engines run at higher temp than water cooled engines so, although automotive oils will work, if you’re looking for long term service the proper rating will be best. Another thing you should do is run the engine at full throttle to keep the fan turning faster to cool the engine.
