For your Yamaha FZS Version 2 bike with 20,000 km on the odometer, it is recommended to use a high-quality engine oil that meets the manufacturer's specifications. In this case, Yamaha recommends using Yamalube 10W-40 engine oil for the FZS Version 2.
Yamalube is the official lubricant brand of Yamaha and is specifically formulated to meet the requirements of Yamaha motorcycles. It provides excellent lubrication, heat resistance, and engine protection. Using the recommended Yamalube oil can help maintain the performance and longevity of your motorcycle's engine.
When choosing engine oil, it's crucial to consider the viscosity grade, which is represented by the numbers before the "W" (winter) and after the hyphen. In this case, 10W-40 indicates that the oil has a viscosity suitable for both cold starts (the "W" number) and normal operating temperatures (the second number).
Always refer to the owner's manual or consult with a Yamaha authorized service center to ensure you select the correct oil for your specific model and year. They can provide the most accurate and up-to-date information regarding recommended engine oils and maintenance guidelines for your Yamaha FZS Version 2.