Well, wikipedia claims the bomber version of the Mosquito had a range of 2400 km with 1800 kg bomb load (good enough for Berlin and back), and B-17G 3200 km ran

Well, wikipedia claims the bomber version of the Mosquito had a range of 2400 km with 1800 kg bomb load (good enough for Berlin and back), and B-17G 3200 km range with 2700 kg bomb load. So 3/4th the range and 2/3rd the bomb load.