When a car dealer quotes you a Money Factor, you can always multiply that by 2400 to get a very good feeling about the actual interest rate %. Also, the monthly payment calculated by the Money Factor is always slightly lower than that calculated by the 'real' formula.
For example, if a dealer tells you his lease Money Factor is .0025, then you simply multiply that by 2400 to get 6. Now you know that the actual interest rate behind this Money Factor is slightly below 6%.
Sometimes a dealer will give you a Money Factor like 3.1 so it sounds like a low interest rate. In this case you just multiply that number by 2.4 and immediately know that the interest rate is about 7.44%.