Alice wanted to see if a new premium gasoline would give her more kilometres per litre. She filled her car with the new gasoline and went on a long trip. When she calculated her mileage, she discovered that she has gone 40 kilometres further on this tank of gas than she went on a tank of regular gas when she was driving around town as usual. She decided to buy the premium gas from then on to get better mileage. What are the errors in this experiment?