My shortest was less than a mile. In fact, the odometer was the same when I dropped it off. I didn't know the cheap car rental place was right at the Crown Plaza hotel in London Heathrow (LHR) and I drove it from the hotel to a pub then back. They asked me if I really drove it and I was too honest so I said yes, "to the pub and back."

I don't know if they were going to dismiss the charges, but I still paid the one-day rental.