Using a SAE 10W-40 car oil in a 4-stroke motorbike is generally acceptable in many cases. However, it's always recommended to consult your motorcycle's owner manual or contact the manufacturer to determine the specific oil requirements for your bike. They will provide the most accurate and reliable information regarding the recommended oil viscosity and specifications.
While SAE 10W-40 is a common viscosity grade used in many motorcycles and cars, there might be variations in the requirements depending on the specific engine design, operating conditions, and lubrication system of your motorcycle. Some motorcycles may require different viscosities or oils specifically formulated for motorcycles, as they may have different additives and friction modifiers to meet the unique demands of motorcycle engines, transmissions, and clutches.
Using the wrong oil viscosity or formulation could potentially lead to performance issues, excessive wear, and even engine damage. Therefore, it's crucial to follow the manufacturer's guidelines to ensure the optimal performance and longevity of your motorcycle's engine.