1 

Operational
Speed

Motorcycles tend to operate at engine speeds significantly higher than automobiles. This subjects lubricating oil to higher loading and shear forces. Elevated RPM’s also promote foaming, which accelerates oxidation and reduces the oil’s load-carrying ability.

2 

Compression Ratios

Motorcycles tend to operate with higher engine compression ratios than automobiles. Higher compression ratios place additional stress on engine components and increase engine-operating temperatures.

3 

Horse Power

Motorcycle engines produce nearly twice the horsepower per cubic inch of displacement of automobile engines. This exposes the oil to higher temperatures and stress.

4 

Variable Engine Cooling

Automobiles use a water-cooling system to control engine temperatures. Many motorcycles are air-cooled or use a combination of air/oil design. This results in elevated operating temperatures, which promotes oxidation and causes oil to thin.

5 

Multiple Lubrication Functions

In automobiles, engine oil is only required to lubricate the engine. Many motorcycles have common sumps for the engine and transmission. Many motorcycles also incorporate a frictional clutch within the transmission that uses the same oil.

6 

Inactivity

Motorcycles are typically used less frequently than automobiles. These extended periods of inactivity put more stress on the oil. Critical concerns are rust and corrosion protection.