What is the impact of switching from 5w30 to 5w40 on the engine?
2 Answers
There is no impact on the engine when switching from 5W30 to 5W40 oil for a car. The specific differences between 5w30 and 5w40 oils are as follows: 1. Different viscosity: 5W-30 and 5w-40 oils have different viscosities, with 40 being slightly higher, meaning the 40 oil has slightly higher fuel consumption. 2. Different performance at low temperatures: 5w-30 performs better at low temperatures because its viscosity is significantly better than 5w-40 under low-temperature conditions. 3. Different performance at high temperatures: Under high-temperature conditions, 5-40 has better stability.
I used to use 5W30 engine oil, but later switched to 5W40. The biggest change I noticed is that the car's fuel consumption has increased. The engine's operating resistance has significantly increased, and the throttle doesn't feel as light and responsive as before, especially in city traffic jams. On average, I'm spending about 30-40 yuan more per month on fuel. However, the high-temperature protection has improved somewhat – during long summer trips, the engine noise is indeed reduced. My suggestion is that if you have a new car or one with low mileage, it's more cost-effective to stick with 5W30 as recommended in the manual. For older cars or those frequently carrying heavy loads on highways, 5W40 might be worth considering.
