Abstract: A vehicular number input device used for entering fuel/energy price information into a vehicle's internal computer, mileage computer, mileage software or software monitoring system. This number input device is secured to the vehicle near the gas cap. The fuel/energy price data entered can then be displayed to show real-time fuel efficiency in terms of dollars and cents during the operation of the vehicle or when it has stopped. The optimal device claimed has the best advantage for fuel cost input since it is simple to use and inexpensive to produce. The location of the device is convenient since a user who is pumping gas/recharging power usually has a few moments to himself to enter numbers while the gas is being filled. It's the perfect opportunity to enter fuel price data into a vehicle's computer. This device provides a simple, unique and convenient option for drivers wishing to view of their vehicle's fuel expense consumption costs as it occurs.