According to the official car manual recommendation, the Lavida 1.4T should use 95 gasoline. In addition to checking the appropriate gasoline grade in the car manual for the Lavida 1.4T, you can also check it on the fuel tank cap, which will also indicate the suitable gasoline grade. Generally, the gasoline grade can also be determined based on the engine's compression ratio. Cars with an engine compression ratio between 8.6-9.9 should choose 92 gasoline, while those with a compression ratio between 10.0-11.5 should choose 95 gasoline. However, with the use of some new technologies, the gasoline grade cannot be solely determined by the compression ratio. A high compression ratio can also be adjusted to use lower-grade gasoline because, apart from the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline grade, the higher the octane number, and the better the anti-knock performance. 92 gasoline contains 92% isooctane and 8% n-heptane, while 95 gasoline contains 95% isooctane and 5% n-heptane. If the Lavida 1.4T occasionally uses the wrong gasoline grade, simply switch back to the correct gasoline grade after use. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower-grade gasoline, using higher-grade gasoline will not cause damage, but the increase in octane number will change the fuel's ignition point, leading to delayed combustion in the engine. This means the engine's power output and thermal efficiency will decrease, resulting in poorer performance. For vehicles recommended to use higher-grade gasoline, using lower-grade gasoline can cause engine knocking. Because the octane number is too low, the gasoline's ignition point decreases, causing it to ignite prematurely during the compression stroke. If the fuel ignites before the spark plug fires during the compression stroke, resistance will occur during the upward stroke. This resistance will make the engine run very unstably. If it's mild knocking, it only increases noise and does not significantly damage the engine. However, if there is noticeable knocking, it indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on the piston and cylinder, and in severe cases, cylinder scoring.
