Kia's midsize sedan is based on the 2002-2005 Sonata produced by Kia's corporate parent, Hyundai, and receives only minor changes for 2006. A redesigned '06 Sonata went on sale in spring 2005; a similarly redesigned Optima is due as an '07 model in mid 2006.

Optima comes in LX and EX models with either a 4-cyl or V6 engine. With the 4-cyl, manual transmission is standard, an automatic with a manual-shift feature optional. The V6 comes only with the automatic. Front side airbags are standard, but no curtain side airbags are offered. All Optimas have 4-wheel disc brakes, but ABS, previously available on both V6 models, is now optional only on the EX V6. No traction control or antiskid system is offered. Four-cyl models have 15-inch wheels, V6 models get 16s. Leather upholstery is optional on EX models. Optima offers warranty coverage of 5-years/60,000-mi. basic, 10/100,000 powertrain, and 5/60,000 roadside assistance.