Towing is thirsty work

FORD six-cylinder engines are generally thought to be thirstier than rival sixes, and it's reasonable to expect consumption to increase significantly when towing something as large and weighty as a caravan. Depending on the conditions, size and weight of the caravan, consumption could double, but to go up four times seems extreme. Do a consumption test with and without the caravan so you have actual numbers to make an accurate assessment.