Your car comes from the factory with a quality synthetic oil. If they replaced it with standard oil, I would have it replaced asap. The filter doesn't have to be changed since it's fresh oil and it will drain down being that it is on top. Ah, the benefits of the filter being on top of the engine! Anyways, I'm in the Florida sun all year round and use one of the best out there, AMSOIL European Formula 5w-40.....