Over the years, the Kia Optima succeeded against stiff competition in the midsize sedan category thanks primarily to its modern styling. It comes in conventional, hybrid and plug-in hybrid versions. The Optima is equipped with a standard 2.4L four cylinder or one of two optional turbo engines: a 178-horsepower, 1.6L four or a 245-horsepower, 2.0L unit. The HEV generates 192 horsepower.