Building on the success of the Prius, Toyota conceived a family of hybrid vehicles based on the pioneering hybrid model. The first spin-off from the new Toyota Prius family plan was a larger capacity Prius v introduced in 2012. Adopting a wagon-like rear section, the Toyota Prius v is little more than five inches longer than the conventional Prius design. The added length allowed up to 67.3 cubic feet of cargo room making it a more attractive hybrid for families. The Prius v utilized the exact same Toyota Hybrid Synergy Drive system as the regular Prius consisting of a 1.8-liter four-cylinder gasoline engine combined with two electric motors. Generating 134 combined horsepower, the hybrid system of the Toyota Prius v's practicality was complemented by a fuel economy ranging up to 44 miles per gallon during city driving. The 2015 Toyota Prius v underwent a major refresh. For 2017, an enhanced Entune audio system is now equipped with Siri Eyes Free technology.