What is the difference between Mobil Super 5w30 and 5w40?
2 Answers
The differences between Mobil Super 5w30 and 5w40 are: 1. Different high-temperature viscosity: 5w30 has lower high-temperature viscosity, better fluidity, and faster engine heat dissipation; 5w40 has higher high-temperature viscosity, poorer fluidity, but less fluctuation and greater stability. 2. Different applicable objects: 5w30 can effectively reduce fuel consumption and has lower noise, making it suitable for new cars or naturally aspirated engines; 5w40 has higher viscosity and is more suitable for older cars. The number after 'W' in the oil model indicates the kinematic viscosity of the engine oil at 100 degrees Celsius. The larger the number, the higher the viscosity, meaning better and more stable protection at high temperatures, with a lower possibility of thinning at high temperatures.
Mobil Super 5w30 and 5w40 mainly differ in viscosity. The number 5w represents low-temperature performance, ensuring smoother starts in cold weather, with smaller numbers indicating faster flow. The numbers 30 and 40 indicate viscosity at high temperatures; 30 is thinner, which can help save fuel and is suitable for daily city driving in newer cars. 40 is much thicker, especially beneficial for highway driving in hot weather, providing better protection for older engines and reducing wear. I've tried driving on mountain roads in hot summer with 40 oil, and the engine was noticeably quieter with less vibration. Most newer car models recommend 30 oil because their engines are more advanced and don’t need such thick oil. However, if your car manual specifies 40, don’t switch to 30 arbitrarily, as it may lead to unstable oil pressure and shorten engine life. In short, choose based on the season and your car type for the best results.
