I paid on my car for over four years and NEVER was late or missed a single payment. Upon paying my loan off my credit score dropped 28 points. Can anyone explain why?

I would give them a call for clarification

I think it's because you're actually making one less payment in a credit account each month. Theoretically getting another car to pay on to show an active payment each month should put u back in the upper numbers. Not necessarily a great way of doing things I would agree with but the way the credit world is operating today.