Currently, fuel probably has the least affect on game play in the MA. Destroying all storage tanks at a field to reduce max fuel load to 75% might mean something to a short-legged fighter, but that has no ill result for bombers. Seems kind of weird that a damaged field would have an equal fuel ration for both small-tanked fighters and large-tanked bombers. It would take way more precious gallons to fill a bomber to 75% capacity as it would for a small fighter. Let's put this in perspective - a fully laden Bf-109F holds 185 gallons of fuel; a B-29 carries 6,650 gallons (almost 36 times more!)
I propose limiting the fuel load by class and not a just a blanket limitation as we currently have it. When all fuel tanks are destroyed at a field, set the maximum fuel load out to 25% for heavy bombers, 50% for medium bombers, and 75% for fighters/light attack aircraft. Could alternatively set the limitation by fuel tank size relative to other planes in the game: large - 25%, medium - 50%, small - 75%. I say that because the La-7 and P-47N would be under the same fighter class, but they carry 123 gallons and 550 gallons, respectively. Perhaps a change like this would enhance the fuel dynamic of the game without it crippling play.