the oil is probably dripping on the exhaust pipe and its burning it off,that's where the smoke is coming from on it,take it and have a shop check it they wont charge you to look at it,and then they can give you a hint of what it might cost to get it repaired,if is rear main seal leaking they will have to either pull the transmission or the engine to replace it and that will be really expensive,and with that many miles on it id say its a good possibility that it could be a rear main seal leaking on it,good luck.
