Of course, a big expense when switching to alternative fuels is the purchase price of a new vehicle already equipped to run on an alternative fuel from an original equipment manufacturer (OEM). However, because this is not a cost that you will have to pay every year, you should divide the price premium by the number of years the vehicle will be used. This calculation process is called amortization.

Another way to take the original vehicle cost into consideration is to figure total operating costs for the lifetime of the vehicle, and add the entire cost to the result.