A 10% reduction would mean you’d get approximately 5 more tons to the Moon (not 300.) The Saturn V was capable of delivering 50 tons to lunar insertion. Reduci

A 10% reduction would mean you’d get approximately 5 more tons to the Moon (not 300.) The Saturn V was capable of delivering 50 tons to lunar insertion. Reducing the fuel requirement improves the payload amount by that percentage. It’s not a direct trade off between the total mass of the vehicle and fuel for more payload.