Using 5W-40 motor oil in a 2013 Honda CR-V should generally be fine. While it's always recommended to use the oil viscosity grade specified by the manufacturer, a slight deviation like this should not cause significant issues or damage to the engine.
The numbers in the oil viscosity rating represent the oil's flow characteristics at different temperatures. The first number (5W) indicates the oil's viscosity at low temperatures, while the second number (40) represents its viscosity at high temperatures. In this case, 5W-40 is slightly thicker at high temperatures compared to the recommended viscosity grade for the CR-V, which is typically 0W-20 or 5W-20.
Using a slightly thicker oil may affect the engine's performance to a small extent, particularly during cold starts. It may result in slightly reduced fuel efficiency and potentially impact engine wear over an extended period. However, the impact is generally minimal, especially if it's a one-time occurrence.
If you're concerned or want to ensure optimal performance, it's recommended to drain and replace the oil with the correct viscosity grade as specified in the owner's manual. This will provide the best protection and performance for your Honda CR-V. If you're unsure or want more specific advice, it's always a good idea to consult with a qualified mechanic or contact a Honda service center for further guidance.