Using a 5W-40 Motul oil in a Gixxer 155 motorcycle should not cause any significant problems. Motul is a reputable brand that produces high-quality oils suitable for motorcycles. However, it's important to consult the owner's manual or check with the manufacturer to confirm the recommended oil viscosity for your specific motorcycle model.
Typically, the manufacturer specifies the appropriate oil viscosity to ensure optimal engine performance and protection. If the manual suggests a different oil viscosity, it's generally advisable to follow those recommendations. Using the recommended viscosity ensures proper lubrication, especially during startup and under different temperature conditions.
If the manual or manufacturer confirms that 5W-40 is an acceptable oil viscosity for your Gixxer 155, you can confidently use the Motul 5W-40 oil without major concerns. Just ensure that the oil meets any other specifications mentioned in the manual, such as API (American Petroleum Institute) or JASO (Japanese Automotive Standards Organization) ratings.
Ultimately, for precise information on oil specifications and recommendations, it's best to consult the owner's manual or contact the manufacturer directly. They can provide the most accurate guidance regarding oil choices for your Gixxer 155 motorcycle.