What are the consequences of using 92-octane gasoline for a long time in the new Passat?
2 Answers
Using 92-octane gasoline in the new Passat for a long time may cause knocking, which can affect the engine's lifespan and the degree of component damage over time. The recommended fuel grade for the new Passat is 95-octane, which was formerly known as 97-octane gasoline. It is advised that owners follow the relevant regulations in the user manual and use the appropriate fuel. Gasoline is a colorless to light-yellow, easily flowing liquid at room temperature, difficult to dissolve in water, and flammable. Its distillation range is between 30°C and 205°C, and it can explode when its concentration in the air is between 74 and 123 grams per cubic meter upon encountering a flame. The characteristics of gasoline are as follows: Evaporability: Gasoline must quickly vaporize in the engine cylinder and form a uniform combustible mixture with air, which is primarily determined by its own evaporability. The main indicators reflecting evaporability are distillation range and saturated vapor pressure. Stability: The ability of gasoline to resist oxidation under normal temperature and liquid-phase conditions is called the oxidation stability of gasoline, or simply stability. The indicators for evaluating gasoline stability include iodine value, actual gum, and induction period. Anti-knock quality: The property that measures whether a fuel is prone to knocking is called anti-knock quality. The anti-knock quality of gasoline is represented by the octane number (RON). The higher the octane number of gasoline, the better its anti-knock quality. Corrosiveness: The corrosiveness of gasoline is related to sulfur and sulfur compounds, organic acids, and water-soluble acids or bases.
I drove a Passat for over a decade and noticed many people opting for cheaper 92-octane gasoline long-term, with truly awful consequences. The engine frequently produced knocking sounds, like hiccups, which ruined the driving experience. Over time, spark plugs accumulated carbon deposits, turning black and brittle, leading to misfires and a stealthy increase in fuel consumption—originally 8 liters per 100 km could easily spike to over 10 liters. The piston rings were also affected, suffering accelerated wear. Repairs weren't just about replacing parts; cleaning carbon deposits alone cost 2,000 to 3,000 yuan. Even worse, my neighbor's engine seized up, with repair bills nearing 30,000 yuan. There's a reason manufacturers recommend 95-octane fuel—higher octane prevents pre-ignition and protects engine longevity. My advice: don't be penny-wise and pound-foolish. Regularly inspect the fuel system during maintenance.
