How do I turn on unlimited fuel in Microsoft Flight Simulator?

To turn on unlimited fuel in Microsoft Flight Simulator, pause the flight or open the main Settings/Options menu, select Assistance Options, expand Aircraft Systems, and switch Unlimited Fuel to On. Apply the change and return to the cockpit. In MSFS 2024, use the settings search if your menu layout labels it differently.

How do I enable unlimited fuel in MSFS 2020 and 2024?

The setting is normally under Aircraft Systems within the simulator's assistance options.

1. Open the menu. Pause your flight, or enter Settings/Options from the main screen before departure.
2. Open Assistance. In Microsoft Flight Simulator 2020, follow Options > Assistance Options > Aircraft Systems. In MSFS 2024, open the Assistance section from Settings; use the settings search for Unlimited Fuel if the categories appear differently.
3. Enable Unlimited Fuel. Change the switch from Off to On. It is normal for the overall assistance preset to change to Custom.
4. Save the change. Use the displayed Apply or Save command if prompted, then return to the flight.

The procedure is fundamentally the same with a keyboard, Xbox controller or PlayStation controller; only the buttons used to open and operate the menu differ.

Can I turn on unlimited fuel during a flight?

Yes, unlimited fuel can normally be enabled during a Free Flight session without restarting the flight.

The switch prevents further normal fuel consumption once it takes effect. It does not automatically restart an engine that has already flamed out, and it should not be treated as an emergency refuelling command.

Does unlimited fuel refill empty tanks?

No. Unlimited fuel prevents fuel from being consumed; it does not necessarily put fuel back into a tank that is already empty. Add fuel through the aircraft's fuel-and-payload interface, load manager or available in-flight Fuel panel, then complete the correct engine restart procedure.

In MSFS 2020, the Fuel panel may be available from the toolbar. Our guide to finding and customising the in-flight toolbar explains how to reveal panels that have been hidden. Some realistic aircraft prohibit in-flight refuelling or require the engines to be shut down first.

Why is unlimited fuel not working?

Unlimited fuel usually appears not to work because the activity restricts assistance, an empty tank is selected, or the aircraft uses its own fuel simulation.

• The activity locks assistance settings: some Career missions, challenges, lessons and scored activities can restrict or override assists. Test the setting in Free Flight to distinguish an activity rule from a simulator problem.
• An assistance preset reset the switch: choosing a preset such as a realism-focused profile after enabling unlimited fuel may turn it off again. Return to Aircraft Systems and confirm that it still reads On.
• Fuel cannot reach the engine: unlimited quantity does not bypass tank selectors, shut-off valves, transfer systems, pumps, mixture controls or condition levers. Make sure a tank containing usable fuel is selected and configured correctly.
• The aircraft has custom systems: complex add-on aircraft may calculate fuel through their own EFB, load manager or internal system. Use the aircraft's own loading controls if the native assistance switch is ignored or overwritten.
• The shutdown has another cause: icing, engine damage, an incorrect mixture, a closed fuel valve or a failed pump can stop an engine even with unlimited fuel enabled.

If fuel is aboard but the engine is being starved, check the assigned selectors, pumps and mixture controls. Our MSFS keyboard and fuel-control command reference lists the relevant default commands, although custom control profiles may use different bindings.

Does unlimited fuel affect aircraft weight?

Yes. Loaded fuel still contributes to aircraft weight, and because it is not burned off, the aeroplane does not become lighter as the flight progresses.

A common mistake is filling every tank and then enabling unlimited fuel. That can produce an unnecessarily heavy take-off and, particularly in an airliner, a landing weight far above the planned figure. Load a sensible departure quantity first, check weight and centre of gravity, and then enable unlimited fuel if you want extended endurance.

The setting changes fuel consumption only. It does not disable engine damage, remove the need to operate the fuel system correctly, or make realistic range and landing-weight calculations meaningful.