What grade of fuel should a normal car use?
3 Answers
Usually, the fuel grade label is marked on the fuel tank cap. The only criterion for selecting the gasoline grade is the compression ratio of the car engine. Generally, the higher the compression ratio, the higher the gasoline grade. Typically, when the compression ratio is between 7.5-8.0, 90-93 grade gasoline should be used; for a compression ratio of 8.0-8.5, 90-93 grade gasoline is suitable; when the compression ratio is 8.5-9.0, 93-95 grade gasoline should be selected; and for a compression ratio of 9.5-10.0, 95-97 grade gasoline is recommended. The manual clearly specifies which grade of gasoline to use. There is no mistake in following the manual's instructions. Generally, the higher the compression ratio, the higher the gasoline grade. However, a high compression ratio does not entirely mean that high-grade gasoline is required. With clever engineering, high-compression engines can also use lower-grade gasoline.
For regular family cars like the Honda Civic or Toyota Corolla that I drive, using 92-octane gasoline is usually sufficient. This isn't just a wild guess—I carefully checked the owner's manual when I bought the car, and the manufacturer recommends 92-octane. I've been using it for over a year, driving in both city and highway conditions, with no issues. Some people think using 95-octane is more premium and can protect the engine better, but my experience is that unless you're driving a performance model like a BMW or Mercedes with a high-compression engine, it's unnecessary to spend the extra money. In fact, using higher-octane fuel might even increase carbon deposits in the combustion chamber and affect fuel efficiency. When refueling, I always go to reputable gas stations and avoid cheap, small shops to ensure fuel quality. In short, following the manual is the most worry-free, cost-effective, and hassle-free approach, and it can even extend the engine's lifespan.
As an average car owner, my top priority is saving fuel and money without harming the vehicle. Regular cars can use 92-octane gasoline, which is the commonly recommended grade for Japanese and Korean family cars. Using 92-octane saves a few cents per liter, adding up to significant fuel savings over a year. However, there's a crucial point to note: always check the manual after buying a car, as compression ratios vary greatly between models. Low-compression engines work perfectly with 92-octane, while higher grades are just a waste. High-compression engines, like those with turbochargers, require 95 or 98-octane to prevent knocking. Avoid randomly switching fuel grades in daily driving, especially mixing different grades, as it can cause engine misfires. I once tried using 90-octane in an old car and immediately noticed reduced performance, so I switched back. Remember, choosing the right fuel grade makes engine maintenance easier and more cost-effective.
