It is generally recommended to follow the manufacturer's recommendations for the recommended grade of engine oil in your Honda Unicorn 160. The user manual suggests using 10W30 grade engine oil, which is selected based on the engine's design, tolerances, and operating conditions.
Using a different grade of engine oil, such as 20W50, may not provide the optimal lubrication and performance for your motorcycle's engine. The viscosity of the oil affects its flow and lubricating properties, which can impact engine protection, fuel efficiency, and overall performance.
While some riders may choose to use a different grade of engine oil for specific reasons, such as extreme hot weather conditions or heavy load riding, it is generally advisable to stick with the manufacturer's recommendations to ensure the best performance and longevity of your engine.
If you have concerns or specific reasons for considering a different grade of oil, it's recommended to consult with a trusted mechanic or contact the manufacturer directly to get their expert opinion and guidance on the matter. They will have the expertise to provide you with the most accurate information for your specific motorcycle model.