How often should you do a oil change on a 4 cylinder 2006 Kia Optima?

If you use synthetic oil and a synthetic oil filter (both are mor expensive) you can go a little longer in between changes. The oil will run about $20 for 5quarts and the filter usually starts about $10. Usually max should be about 7,000 miles though some say more but its not recommended to go pass 7,000 miles. You can not change the oil to often. I do it every 2000 mi. a lot of people say 3000. That would be the max. I would let it go. Even if you have someone else do it there should be someplace that charges between $20 and 30 for just an oil change. Much cheaper than a new motor or car.