What grade of gasoline should be used for the Jetta VS5?

[DeSimon]

Jetta VS5 requires 95-octane gasoline. The Jetta VS5 is equipped with a 1.5-liter turbocharged engine across all models. Generally, such turbocharged engines require the use of 95-octane gasoline to prevent engine knocking. Knocking is an abnormal combustion phenomenon in the engine. When the piston is in the compression stroke, it moves upward to compress the combustible mixture, causing the temperature and pressure of the mixture to rise. If the combustible mixture ignites before the spark plug fires, this is known as knocking. The burning mixture pushes the piston downward, but since the piston is moving upward at that moment, this can negatively affect the engine's power output and fuel consumption.