Jetta VS5: Should I Use 92 or 95 Octane Gasoline?

[JuniperFitz]

Jetta VS5 requires 95 octane gasoline. According to the manufacturer's specifications, the Jetta VS5 should be fueled with 95 octane gasoline, as it provides better protection for the engine. More details are as follows: 1. The type of gasoline to use should follow the manufacturer's recommendations. Car owners do not need to choose the gasoline grade based on the compression ratio. There is no fundamental difference in quality between 92 and 95 octane gasoline, and neither contains fuel impurities. 92 octane gasoline consists of 92% isooctane and 8% n-heptane, while 95 octane gasoline consists of 95% isooctane and 5% n-heptane. 2. During the design phase of a car engine, the required gasoline grade is determined based on the compression ratio. The compression ratio is a crucial structural parameter of the engine, representing the ratio of the gas volume when the piston is at the bottom dead center (start of compression) to the gas volume when the piston is at the top dead center (end of compression). From the perspectives of power and fuel efficiency, a higher compression ratio is generally better. A high compression ratio improves power output, thermal efficiency, and enhances vehicle acceleration and top speed.