21,500 BHP.. 21 days (right?).. at 20 knots.. A very very rough guesstimate would be that it uses 50 tonnes per day or around 1,000 tonnes per trip. If it carries 5,000 cars then it's 200 kg or 230 liters of diesel per car for the trip. At 20 km/l that equals 4,600 km for a diesel car. Keep in...