Want to see the economic savings of owning a fuel-efficient hybrid car? Buying a new hybrid costs more, and it can take up to six years before you start saving money on fuel costs, according to the car site edumunds.com. To start seeing savings quickly, consider buying a lightly used hybrid car. The fastest and cheapest way is to look at the inventory of hybrid cars for sale by national car rental companies. You can search their databases of used hybrids, see their no-haggling prices online and even check out the cars in your local area. Search car rental agency names and “car sales” to find online databases.