Should the LaCrosse use 5w30 or 5w40?
2 Answers
The original factory oil specification for the LaCrosse is 5W30, so it is recommended to use oil with the same specification as the factory. Below is relevant information about engine oil: 1. The 'W' in oil stands for winter. The smaller the number before the W, the lower the viscosity at low temperatures, the better the low-temperature fluidity, and the lower the minimum applicable temperature. The number after the W indeed refers to the oil's viscosity at 100 degrees Celsius; the larger the number, the higher the oil's viscosity. 2. In terms of all-season universal oils, both 5w-30 and 5w-40 are considered universal oils, so they can be used in any season and also protect the engine.
I've been driving the LaCrosse for over three years, mainly for urban commuting, and have always used 5W-30 oil. Buick's manual recommends this grade because its moderate viscosity suits regular driving—it's fuel-efficient and ensures quick cold starts, especially smooth when firing up in sub-zero winter temperatures. The thicker 5W-40 offers better high-temperature protection, but I only occasionally use it for long trips or spirited driving, noticing a slight fuel consumption increase. Never skip regular maintenance—I change oil and inspect every 5,000 km to prolong engine life and prevent carbon buildup. Choosing the right oil is the first step to engine health.
