Can You Use Motor Oil Instead Of Motorcycle Oil?

Motorcycle Oil being made by Castrol®

Can you use regular oil in a motorcycle?

Motorcycle oils are like oils that are used in passenger car, but there are some key differences between the oils needed to protect a motorcycle. The difference is related to how lubricants flow in a motorcycle as compared to a car. Using the correct oil is very important to making sure that you are protecting your motorcycle properly.


What is the difference between motorcycle oil and motor oil?

 Like car engines, motorcycles have many moving metal parts that need to be cooled and protected as the engine is running. But there are a few key differences that should be considered when buying and adding a motorcycle oil to your bike. 


The first factor is the oil sump size of a motorcycle is significantly smaller than an automobile. This means there is a lot less oil in the engine at any time. In addition, motorcycles often run much hotter and at higher speeds than cars. Since there is less oil cycling through the engine and the oil must cool parts that may be hotter than a car engine, the oil is working harder and faster than a passenger car oil. This could cause the oil to break down faster and lead to engine issues if the right oil is not used.


But the key difference between the lubricant requirements of a motorcycle oil versus a passenger car oil is where the oil must protect. In a car engine, the oil protects only the engine. Different fluids (such as transmission fluids) protect other key areas of the car engine. Motorcycles have a common sump and motorcycle oil is required to protect not only the engine but also cool and lubricate the clutch and gearbox. 


While protecting the engine, motorcycle oils must protect against oxidation, wear, friction and deposit formation similar to a passenger car motor oil. However, since a motorcycle engine is much smaller than a car engine, the oil must be formulated to travel smoothly through the narrower pathways. Passenger car motor oils also contain friction modifiers which could lead to slipping and acceleration loss in a motorcycle. And modern cars require lower viscosity motor oils that may not protect gears properly in a motorcycle and could lead to gear failure.

Green car vs man on a bike

Types of Motorcycle Oils

 Similar to passenger car motor oils, motorcycle oils are available in

  • Conventional (or mineral)
  • Synthetic blend (or part synthetic)
  • Synthetic products 

 Is synthetic oil better for motorcycles?

As with passenger car motor oils, synthetic motorcycle oils provide the best protection at extremes in temperature and have lower oil burn off (volatility) than the other oils.  Synthetic motorcycle blends will perform better than conventional products in terms of temperature and burn-off protection.


Motorcycle manufacturers typically require higher viscosity oils than passenger cars. Motorcycles often call for grades such as 5W-40, 10W-40, 10W-50 and 20W-50. As with cars, always check your vehicle owner’s manual to make sure you are using the correct grade of oil for your bike.


Castrol offers a wide range of products specifically formulated for motor oils, including

  • Conventional Castrol Go! 4T,
  • Synthetic blend Castrol Act>evo 4T and
  • Full-synthetic Castrol POWER1 4T.

These products are available in many grades for all types of motorcycle applications.  And if your bike is a 2-stroke engine, Castrol 2T is available for your needs. To determine the best lubricant for your motorcycle, please check your owner’s manual or visit the Castrol Oil Selector webpage.

Castrol Power1, Actevo and Go! bottles