<human>:  What is the most fuel-efficient car to buy for a small family?
<bot>: The most fuel-efficient car to buy for a small family is the Toyota Prius. It is a hybrid car that combines a gasoline engine and an electric motor to maximize fuel economy. It has an EPA-estimated fuel efficiency of 58 mpg city and 53 mpg highway, making it one of the most economical vehicles on the market. It also offers plenty of features that make it ideal for families, such as reliable safety features, a roomy interior, and low emissions.