For balancing power and fuel efficiency, the 2015 Kia Optima engine is praised. The 2.0-liter turbocharged option offers an exciting 274 horsepower for those seeking more excitement, while the regular 2.4-liter engine delivers solid daily driving with an EPA-estimated 23 MPG city and 34 MPG highway. https://tagoreautoparts.com/engine/kia-optima-Engine