Dear Kia Optima Owner: Kia Motors America, Inc. is conducting an important Product Improvement Campaign to perform a software update on all 2016-2018 MY Optima vehicles equipped with 2.4L Gasoline Direct Injection (?GDI?) and 2.0L Turbocharged GDI (?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?).