The 2.0L Hyundai Theta II 4-cylinder was released in 2011 and has become a popular powerhouse since then. The 2.0L Theta has been used in numerous Hyundai and Kia vehicles including the Hyundai Sonata, Kia Forte, and Kia Optima. The Theta’s small form factor and solid power output make it a fan favorite. Learn more about the 2.0L Theta 4-cylinder including specs, common problems, and more.