Should the Buick LaCrosse 2.4L use 95 or 92 octane gasoline?
2 Answers
The Buick LaCrosse 2.4L should use 95 octane gasoline. The difference between 92 and 95 octane gasoline: Their main components are that 92 octane gasoline consists of 92% isooctane and 8% n-heptane, while 95 octane gasoline consists of 95% isooctane and 5% n-heptane. The reason why 95 octane gasoline is slightly more expensive is that it has a higher proportion of isooctane. The importance of choosing the right gasoline: Every car's manual mentions a term called compression ratio. Generally, if a high-compression-ratio engine uses low-octane gasoline, it can lead to incomplete combustion, strong engine vibrations, reduced power output, damage to engine components, increased fuel consumption, and weak driving performance. Conversely, if a low-compression-ratio engine uses high-octane gasoline, it can result in delayed combustion, meaning the fuel does not reach its auto-ignition point even at maximum compression. This also leads to incomplete combustion, requiring more fuel injection to ensure power output, which not only offers no benefit to the engine but also increases fuel consumption.
I often help friends with such car-related questions. The Buick LaCrosse 2.4L is equipped with a naturally aspirated engine, and according to general car manual guidelines, it is designed to run on 92-octane gasoline. The octane rating of 92-octane fuel meets the engine's requirements and prevents knocking issues. If you upgrade to 95-octane, the anti-knock performance is slightly better, but it's not necessary and may just cost more without significant benefits. In daily use, I've driven similar models, and they run smoothly with 92-octane fuel while maintaining good fuel economy. However, it's important to note that you should always refer to your car's user manual, as specifications may vary slightly depending on the model year. Using the wrong fuel grade long-term, such as mixing fuels or using a grade that's too low, could increase emissions or slightly reduce performance. Therefore, developing the habit of using the correct fuel is crucial for prolonging engine life.
