Does Using Reserve Fuel Damage a BMW?

[StJameson]

Using reserve fuel can damage a BMW. The fuel pump is typically located inside the fuel tank, but when the tank is empty, the pump is exposed to air, lacking lubrication, which can affect its lifespan. Therefore, it is advisable to avoid using the reserve fuel tank and not to drive until the tank is nearly empty before refueling. Below are some precautions for fuel tank usage: 1. Do not wait for the low fuel warning light to come on before refueling: Drivers should check the fuel gauge before driving and calculate whether refueling is needed based on the trip distance and the fuel gauge reading. It is better to refuel in advance rather than waiting for the warning light to come on. The fuel pump is located inside the tank and operates at high temperatures when continuously working; being submerged in fuel helps cool it effectively. When the warning light comes on, it indicates the fuel level is below the pump. Repeatedly waiting for the light to come on before refueling can shorten the pump's lifespan, and having too little fuel in the tank may even cause the pump to burn out. 2. Choose to refuel in the morning or evening: Generally, temperatures are lower in the early morning and evening, and gasoline has a lower vaporization point. Therefore, it is better to refuel during these times. Gasoline expands with heat and contracts with cold, and it is sold by volume. At lower temperatures, gasoline has a relatively higher density, meaning more mass per unit volume, so you get more fuel for your money. 3. Avoid filling the tank completely when driving in the city: When driving in urban areas, there is no need to fill the tank completely. A full tank adds extra weight to the engine, increasing fuel consumption. Since refueling is convenient in the city, there is no need to fill the tank to the brim.