Honda lawn mowers are high-end lawn care products that are very reliable. However, without proper maintenance, they will be far less reliable. Regular oil changes are required as standard maintenance for any internal combustion, gasoline engine like those used in Honda mowers. By understanding your lawn mower's engine oil requirements, you can select a suitable engine oil for the required oil changes.
According to the Volvo Club of the United Kingdom, petroleum-based engine oils were developed as a high-temperature lubricant. Lower temperature applications often used mineral oils, which break down at temperatures higher than about 210 degrees F. Oils recommended for Honda lawnmower engines are commonly available motor oils.
The purpose of the oil in the engine of your Honda lawn mower is the same as with any other internal combustion engine. The slippery oil adheres as a thin film to the moving parts of the engine, reducing friction and heat. By reducing friction and heat, wear to the moving parts of the engine is also reduced.
There are two general types of motor oils. The older, more traditional oil is petroleum based. However, a number of manufacturers have created synthetic motor oils that don't break down as quickly as petroleum-based oils. Although Honda recommends petroleum-based motor oils, any synthetic motor oil that meets or exceeds the specifications in the owner's manual for your particular mower will work.
Motor oils are divided into SAE ratings. SAE ratings define the oil's viscosity. The higher the rating, the thicker the oil. Thicker oils can tolerate more heat than thinner oils. However, thicker oils may not work well in very cold climates. Thinner oils may break down under the high heat of an air-cooled engine, like the one in your Honda lawn mower.
Because lawn mowers are not used in sub-zero temperatures, Honda and Mobile Oil both recommend standard 10W-30 oil for your Honda lawn mower. SAE 30-weight oil is in the middle of the SAE ratings. SAE 10 and 20 may not provide the high heat protection your engine requires. SAE 40 and 50 may be too thick to flow freely around the parts of your Honda mower's engine.