20:29 03-02-2026

How much fuel to keep in your tank for best car performance

Many drivers believe keeping the fuel tank constantly full is the best approach. This view is supported by the American Automobile Association (AAA), especially during winter, as a full tank is thought to reduce the risk of condensation forming inside the fuel system. However, this method has its downsides—frequent trips to the gas station and a lack of real practical necessity.

Auto mechanics generally agree that for most everyday situations, the optimal fuel level ranges from one-quarter to a full tank. This reserve is considered the sweet spot between safety, convenience, and maintaining the vehicle's technical condition.

Maintaining at least a quarter tank is crucial primarily to protect the fuel pump. In modern cars, the pump is often located directly in the tank and is cooled by the fuel itself. When gasoline levels are too low, the pump operates at higher temperatures, accelerating wear. Additionally, fuel serves a lubricating function; at low levels, the supply becomes unstable, and the pump's working conditions deteriorate.

On the other hand, constantly "topping off" to the brim isn't recommended either. Excess fuel can negatively impact the evaporative emissions control system, and there's no practical benefit unless under special operating conditions.

There are situations where mechanics do advise keeping the tank more than half full. Primarily, this applies in winter, especially during severe cold snaps or snowstorms. In such conditions, a larger fuel reserve means more time for the engine and heater to run if the car gets stranded far from help. Moreover, winter often brings long lines at gas stations or power outages that can temporarily shut down fueling stations. In these cases, having extra fuel provides added peace of mind.

Some drivers claim they've driven for years "on the warning light" without encountering issues. Technically, this is possible—a car won't break down instantly due to low fuel levels. But mechanics compare this practice to chronic neglect of health: some may endure it, while others face consequences sooner and at a higher cost.

The takeaway is straightforward: for everyday driving, it's best to keep fuel levels between a quarter and a full tank. Neither running on empty nor constantly maintaining a full tank offers advantages, and in some cases, they can even cause harm. The exception is extreme winter conditions, where a fuel reserve can truly make a decisive difference.