How Running Your Car Near Empty Affects Engine and Fuel System

Driving with a low fuel level can lead to accelerated wear of the fuel pump and cause difficulties starting the engine in cold weather. This was explained to Pravda.Ru by independent automotive expert Sergey Petrov.

Why a Quarter Tank Is the Minimum

Petrov emphasized that most automakers advise against letting the fuel level drop below a quarter of the tank. This recommendation is not only about prolonging the life of the fuel system but also about preventing technical issues during extreme temperatures.

"The minimum fuel level should be at least a quarter of the tank. In hot weather, it is important for the fuel pump to be properly cooled, since cooling occurs through the fuel. In cold weather, moisture and condensation can form in the tank, and at low fuel levels they can freeze and prevent the car from starting. The risk always exists depending on fuel quality and refueling conditions."

Risks of Driving Near Empty

The expert noted that regularly driving with an almost empty tank negatively affects the fuel system. When the fuel level is low, the pump may draw in air, leading to irregular fuel supply and accelerated wear of pump components.

"Low fuel levels and constant driving in this mode can lead to accelerated wear of the fuel pump and overheating. This is especially relevant when driving uphill or downhill, as the pump may draw in air, causing uneven operation of the fuel system."

Seasonal Recommendations

Petrov recommends keeping the tank full during winter to avoid engine-start issues caused by frozen condensation. In summer, he suggests maintaining a small empty space in the tank to allow for fuel evaporation.

"In cold weather, it is recommended to fill the tank completely to avoid problems starting the engine, while in summer, it is advisable to leave a small free space in the tank to allow for fuel evaporation."