F1 is the pinnacle of open wheel, single seater car racing and arguably the highest level of any motorsport globally.... There's more... In 2022 F1 cars run on 87 octane fuel which is 10% ethanol As part of their green strategy, Formula... There's more... tanks/bladders are still not pressurised and have a fuel breather system to let air in.
Although it sounds safer to have no air, just fuel in the bag, it isn’t. Air is a good cushion for impacts, and the tank has several baffles and valves to prevent any slushing around.
Read more on F1 fuel at motorsportexplained.com – here