I was just referring to the radii with dates for the P-47 and Spitfire, until a certain number of missions had been made to push the LW back, putting tanks to go further didnt make a great deal of sense was how I saw things or is that wrong?The only tanks dropped early were the 200/205 gal un-pressurized C/L Ferry tank somewhere 18K - often with half a tank of fuel remaining. Otherwise drop when attacked. BTW that is why ALL Combat Radius charts are prepared based o longest datum for which a fight and return flight home is solely on internal fuel available.