The 2006 Kia Optima is available as a 4-door, 5-seat sedan. Starting at $19,100, the 2006 Kia Optima EX (A4) is powered by a 2.4L , 4 -cylinder engine mated to an automatic transmission that returns an EPA estimated 22-mpg in the city and 30-mpg on the highway. The top of the line 2006KiaOptimaLX (A4) , priced at $ 17,650 , is powered by a 2.4L , 4 - cylinder engine mated to an automatic transmission that returns an EPA estimated 22-mpg in the city and 30-mpg on the highway.