Using 20W-40 engine oil instead of the recommended 20W-50 oil may have some consequences for your bike's engine, especially considering your daily mileage of 100km. Here are a few potential issues you may face in the long run:
Lubrication: The viscosity of engine oil determines its ability to lubricate the engine components effectively. 20W-50 oil is thicker than 20W-40, providing better lubrication and protection, particularly at higher temperatures. Using 20W-40 oil could result in reduced lubrication, potentially leading to increased friction and wear on the engine parts over time.
Engine Wear: With inadequate lubrication, the engine's moving parts, such as pistons, rings, and bearings, may experience increased friction, resulting in accelerated wear and tear. Over an extended period, this can lead to reduced engine performance, increased fuel consumption, and potentially costly engine repairs.
Oil Consumption: The use of a thinner oil like 20W-40 may increase oil consumption, as it may burn or evaporate more quickly. This could lead to more frequent oil top-ups and potentially leave the engine with insufficient lubrication if not monitored closely.
Heat Dissipation: Thicker oils generally provide better heat dissipation capabilities, helping to keep the engine temperature within optimal limits. Using a thinner oil, like 20W-40, may compromise the engine's ability to dissipate heat effectively, potentially leading to overheating issues, especially during long rides or in hot weather conditions.
It's worth noting that these effects may not be immediately noticeable, but they can gradually accumulate over time. To ensure the longevity and optimal performance of your bike's engine, it is generally recommended to use the oil grade specified by the manufacturer. If you have concerns or are considering a different oil grade, it's advisable to consult your bike's owner manual or a trusted mechanic for specific recommendations based on your bike's make and model.