Is 5w30 or 5w40 better for 100,000 kilometers?
2 Answers
Using 5w40 engine oil would be better. Increasing the viscosity of the engine oil can enhance the sealing effect, thereby improving engine performance. For vehicles of this age, 40-grade oil provides better performance than 30-grade. Here are the specific details: 1. Introduction to 5W30: 5W30 has a lower high-temperature viscosity, better fluidity, which helps reduce fuel consumption and allows the engine to dissipate heat faster. For engine oils of the same quality grade, 5W-30 has better fluidity than 5w-40, further reducing fuel consumption and enabling quicker heat dissipation for the engine. 2. Introduction to 5W40: 5W40 has higher high-temperature viscosity, is thicker, has poorer fluidity, greater resistance, but less fluctuation and is more stable. For older vehicles, using 5W-30 oil may result in slightly louder engine noise compared to using 5W-40 oil.
I've been a car repair master for over a decade and often encounter this issue. When a car reaches 100,000 kilometers, internal engine components like piston rings and bearings begin to wear, causing increased clearances. At this point, using 5W40 is better than 5W30. 5W40 has a higher viscosity, which forms a thicker oil film under high temperatures, effectively filling gaps and preventing oil leaks and premature wear. Remember, choosing engine oil isn't solely about mileage—the key is the owner's manual recommendations. If the manual specifies 5W30, don't change it arbitrarily. But if the car feels more vibration or has low oil pressure, 5W40 provides better protection. Regular maintenance is crucial—check oil pressure every 5,000 kilometers and don't skimp on it. Overall, 5W40 enhances reliability and ensures safety during long-distance driving.
