What are the effects of switching from 5w30 to 0w40?
3 Answers
Switching from 5w30 to 0w40 will affect fuel consumption. Here is the relevant introduction about 5w30: 1. 5: The number 5 represents the ability to withstand an external low temperature of -30 degrees Celsius. The smaller the number, the lower the ambient temperature it can be used in, and the better the oil's fluidity in low temperatures, indicating the lowest applicable temperature. 2. 30: The number 30 represents the kinematic viscosity standard at 100 degrees Celsius. This number indicates the oil's high-temperature resistance. The larger the number, the better the oil's protective performance at high temperatures. 3. W: W stands for winter.
I remember I used to use 5W30 oil, but after switching to 0W40, the fuel consumption increased slightly. During daily driving, the engine sound became muffled on the highway, and the power didn’t feel as responsive as before. However, cold starts were noticeably smoother, unlike the previous struggle. I guess higher viscosity oil flows less efficiently at low temperatures but offers better high-temperature protection. But if the car is new or specifies 5W30, using thicker oil might increase internal engine resistance, accelerate long-term wear, and even risk oil seal leaks. Later, I checked the manual and switched back to the manufacturer’s recommendation to avoid engine issues and unnecessary repair costs. I suggest you check your vehicle’s manual first—if it’s not suitable, change it promptly before fuel consumption worsens and regrets set in.
Changing engine oil is not something to be taken lightly. Switching from 5W30 to 0W40 can have varying impacts on your car. A lower number before the 'W' means better lubrication during cold starts, reducing engine wear during winter ignition. However, a higher number after the 'W' indicates thicker oil at high temperatures. For compact cars or low-horsepower engines, this could increase fuel consumption by 5%-10% and result in sluggish power output. I've seen cases where improper oil changes led to valve lifter wear, especially noticeable in older vehicles. If you frequently drive in high-temperature areas or engage in aggressive driving, the thicker oil film of 0W40 might offer better protection. But for daily commuting, it's often not worth the trade-off. Always check your vehicle's manual and consult a repair shop before making a decision to avoid costly engine repairs.
