The 2001 through 2005 model year Magentis were mechanically identical to their sister car, the Hyundai Sonata. Thereafter the Kia Optima differed only from the Sonata in exterior styling and options.
The styling of the Magentis/Optima was revamped for the 2003 model year. American models did not wear the Kia logo on the grille, but the Kia logo was used with that grille for Canada. The grille was redesigned for 2004 to feature the Kia badge, and the headlights were restyled for 2005.
The revised Optima was launched in November 2005 in Korea; and for North America on January 9, 2006 at the North American International Auto Show, now differing to a greater degree from the Sonata. In Australia, the car was renamed as the Magentis.
Unlike the previous Optima, this vehicle no longer shares its platform with the current generation Sonata (NF) nor Hyundai Elantra (HD). It instead uses a global platform, unique to Kia, designated "MG," shared with the Kia Carens/Rondo.
The car continues to be built in South Korea. The current Optima/Magentis shares its 2.4L I4 engine with the Sonata, and uses a 5-speed "Sportmatic" automatic or 5-speed manual transmission.
The Optima received a crash test rating of 5-stars from the NHTSA and 4-stars from Euro NCAP.
The Optima received a redesigned front end and new taillights for the 2009 model year. This facelift debuted at the 2008 New York International Auto Show. In South Korea, it is marketed as the Lotze Innovation (hangul:로체이노베이션). The pre-facelift styling continues to be used on a new model called the Lotze Advance. Noticeable differences from the North American model include LED taillights, different grille, and more options such as push-button start.
The new Theta II 2.4L 4-cylinder engine employs Dual Continuously Variable Valve Timing (CVVT) and a Variable Intake System (VIS) to increase power to 175hp (128.8 KW) while returning improved fuel consumption over its predecessor. The 2.7L V6 has few changes to the previous model, though power is increased to 190hp. Torque figures are 169lb/ft and 184lb/ft respectively. A 5-speed manual transmission is standard in the base model, and a 5-speed automatic is included with mid and high end trims (or as an option in the base model).