In 1967 my partner and I took over a bankrupt car rental company and had three rental stations, Miami, 5th Street on South Beach and the third in Ft. Lauderdale. 8 Person Passenger Van Rental at the time Yellow Rent A Car, owned by Yellow Cab of Miami, with rental stations in Miami and Ft. Lauderdale was offering a sub-compact car with unlimited free mileage at $45 a week. They were the first and only car rental company with free mileage but with a one week minimum rental requirement.
I can not tell you what year they first offered free mileage but I can guess why. They were only in South Florida, Cheap Seven Seater Hire they were only dealing with the leisure market and Disney World 200 miles north was not open. Renters did not use a lot of miles. The competitive rate for a sub-compact car back in the 1960s was $5 per day, $25 per week [5 times the daily rental] and 5 cents per mile. With a one week minimum rental at $25 and with their weekly rate of $45 they would have the difference, or $20, to cover the cost of the miles. At 5 cents a mile the client could use up to 400 miles for the week and the rental would be a wash. I found out later that this was a winner for Yellow Rent A Car.