The 2013 kia optima has a timing chain. your air filter needs to be changed every 15,000 to 30,000 miles. the coolant needs to be changed every 60,000 miles. the spark plugs need to be changed every 100,000 miles unless it's a copper one. a cooper spark plug needs to be changed every 30,000 miles. you will come into many problems with an engine. you can have oil leaks and those need to be fixed as soon as possible. a gasket may be loose and that needs to be tightened up quickly. a spark plug may pop off, causing engine trouble. there could be excessive oil use, requiring the oil to be replaced sooner than expected. a really serious problem is the engine overheating. this may lead to fires and the car exploding.
The 2013 kia optima comes with a timing chain and not a timing belt, which is meant to last for the life of your vehicle engine
The 2013 kia optima has a timing chain instead of a belt