What are the differences between 5w20 and 5w30?
3 Answers
5w20 and 5w30 mainly have the following differences: 1. Different oil viscosity: The difference between 5W-20 and 5W-30 is only the latter number. 5w20 has lower viscosity (viscosity between 5.6-9.3), which is relatively fuel-efficient and makes the vehicle feel lighter, while 5W-30 has higher viscosity (viscosity between 9.3-12.5), which is relatively more fuel-consuming and the throttle feels heavier, but the engine noise is slightly quieter. 2. Different sealing performance: The higher the viscosity, the better the sealing performance. However, a higher number is not always better because the higher the viscosity, the greater the friction, and the greater the engine power loss.
The difference between 5W20 and 5W30 motor oil is something I've often pondered during oil changes after years of driving. The first number represents low-temperature viscosity—both being 5W means they have similar fluidity during cold starts, which is helpful for winter startups without worrying about freezing. The key difference lies in the 20 and 30: the 30 is slightly thicker at high temperatures, providing better engine protection, especially when climbing hills or during long-distance driving to reduce wear. The 20, being thinner, helps lower fuel consumption, potentially saving about half a liter per 100 kilometers. The choice depends on your car's manual recommendation—modern cars often use 20 for fuel efficiency, while older cars or SUVs are better suited for 30 under high loads. Avoid switching oils arbitrarily, as it may affect engine lifespan; consult a professional during regular maintenance. Also, in high-temperature summer regions, 30 helps prevent overheating, but 20 is fine for city driving—just don’t deviate too far from the recommended grade.
The difference between 5W20 and 5W30, as someone who enjoys tinkering with modified cars, what I care about most is naturally the performance impact! The low-temperature performance is the same; the main difference lies in the high-temperature viscosity. The lower number (20) means thinner oil, which allows the engine to run more smoothly, making acceleration feel lighter and throttle response much quicker. The higher number (30) means thicker oil, providing extra cushioning for pistons and bearings during track days or high-speed runs, reducing metal friction and offering better protection. But this depends on the vehicle. For example, turbocharged engines may benefit from 20-grade oil for fuel efficiency but carry a risk of oil consumption, while naturally aspirated engines are safer with 30-grade. Don’t just focus on viscosity—oil quality matters too, with full synthetic offering better durability. Climate is also key: 20-grade is easier to start in extreme northern cold, while 30-grade helps prevent overheating in southern heat. In short, oil selection isn’t fixed—adjust based on driving habits. Occasionally switching is fine, but avoid long-term use outside the recommended range.
