PRODUCT IMPROVEMENT CAMPAIGN (PI1803) - OWNER LETTER - Dear Kia Optima Owner: Kia Motors America, Inc. is conducting an important Product Improvement Campaign to perform a software update on all 2011-2013 MY Optima vehicles equipped with 2.4L Gasoline Direct Injection (?GDI?) and 2.0L Turbocharged GDI (?T-GDI?) engines, and some 2014 MY Optima vehicles equipped with 2.4L GDI and 2.0L T-GDI engines to protect the engine from excessive connecting rod bearing damage. The update will be done free of charge and will only involve the addition of newly developed computer software for the Engine Control Unit (?ECU?).