Craftsman lawnmowers use SAE 30 oil, which is the standard small engine oil. This is a type of all-purpose oil that can be used in push mowers and riding mowers.
Craftsman mowers can also use synthetic 5W-30 oil because it protects the engine for longer in all temperature conditions. Briggs and Stratton also recommends 10W-30 oil, but in temperatures higher than 80 degrees Fahrenheit, the engine begins to consume more oil. Synthetic 5W-30 oil is recommended for use in only winter weather conditions.
Using the wrong kind of oil in a lawnmower can damage the engine and lead to costly problems. Although car engines work by the same combustion principles, car oil should not be used in lawn mowers. Oils come in different viscosity levels, which is the thickness of the oil. SAE 30 is a thicker oil than a SAE 20 oil. Be sure to always check oil levels before using a Craftsman lawnmower.