SAE (Society of Automotive Engineers) classifies motor oils based on their viscosity, with lower numbers indicating thinner oils and higher numbers indicating thicker oils. For a 1998 lawn mower, SAE 30 is a relatively lightweight oil suitable for warm climates or summer conditions, while SAE 10W-30 is a multi-viscosity oil that provides better performance in colder temperatures and varying conditions.
Here are some additional tips for choosing the right oil for your lawn mower transmission:
• Refer to the owner's manual or consult with a qualified repair person to ensure you select the correct oil type.
• Avoid using automotive oils, as they may contain additives that can damage the transmission seals.
• If the transmission has a separate oil reservoir, make sure to fill it to the appropriate level indicated by the manufacturer.
• Regularly check the oil level and change the oil according to the maintenance schedule in the lawn mower's manual.