Should the Buick Regal use 5W30 or 5W40 engine oil?

[MacTessa]

Buick Regal uses 5W30 engine oil. Compared with 5W40, 5W30 has the same low-temperature fluidity but differs in high-temperature performance. 5W40 has higher viscosity, providing better high-temperature protection and sealing performance. However, the increased viscosity results in greater engine running resistance and higher fuel consumption. For the Regal's engine, 5W30 engine oil is more suitable. 5W refers to the range of ambient temperatures in which the oil can be used, indicating its viscosity grade. It can be used in extremely cold regions during winter, with temperatures ranging from -40°C to -10°C. This viscosity grade of oil is relatively thin, with excellent low-temperature fluidity, resulting in relatively low running resistance at low temperatures and making it easier to start the car. Key factors to consider when choosing engine oil: The selection of engine oil should be based on the requirements of the engine. It is unnecessary to use overly advanced oil in engines with lower requirements, nor should lower-grade oil be used in engines with higher requirements. Precautions for changing engine oil: The engine must be preheated before draining the oil. At this time, the oil is thinner and flows more easily, helping to carry away impurities and ensuring thorough drainage. Remember not to drain the oil when the engine is cold, and replace the oil filter simultaneously. The old oil filter may be clogged with impurities, and a blocked oil filter can slow down oil flow and reduce engine lubrication. The amount of oil added should be measured, and for some vehicles, the oil level can be checked with a dipstick to ensure it is within the proper range.