How to Use an Auxiliary Fuel Tank in a Car?
2 Answers
The main and auxiliary fuel tanks are essentially the same tank, but they use a valve to select the fuel level height, reminding the driver to refuel in time. The principle is that when using the main fuel tank, the valve is at the high position of the tank, and when using the auxiliary fuel tank, the valve is at the low position of the tank.
My off-road vehicle has been equipped with an auxiliary fuel tank for three years, and I’d like to share some practical tips with you. Before driving, remember to unscrew the vent valve of the auxiliary tank; otherwise, fuel won’t be drawn. The main/auxiliary tank switch is usually located under the driver’s seat—flip it, and you’ll hear the fuel pump humming. On long trips, it’s best to switch when the main tank is half full. Never wait until the fuel gauge warning light comes on, as this can easily damage the pump. Key point: Always fill both tanks to roughly the same level when refueling, or the vehicle may tilt. Once, my main tank was full while the auxiliary was empty, and I clearly felt instability when cornering. The auxiliary tank needs regular cleaning, especially if you frequently drive on rough roads—sediment buildup can clog the filter. Before installation, always verify the spare tire well dimensions, as auxiliary tanks on the market range from 30L to 120L in capacity.
