The 2008 Toyota Highlander Hybrid gets an estimated 29 mpg combined (31 mpg city/27 mpg highway). It uses an intelligent hybrid system called Hybrid Synergy Drive that selectively uses the gasoline engine and electric motors for optimal fuel efficiency. An electric control unit constantly monitors all vehicle systems to operate the hybrid system safely and efficiently. Additional technologies like regenerative braking and an electric all-wheel drive system further improve fuel efficiency.