Follow up from my last post. This my first oil change on my new 2018 Hyundai Elantra SEL 2.0. I pull into dealership and over to service for scheduled oil change. [censored]? I bought Pennzoil Ultra plat sn plus. Service advisor tells me I cant use it. It will float my gaskets. She Marcy stated Hyundai recommends Synthetic blend QS. Marcy also stated I need to wait at least 3 oil changes before full synthetic can be used. Then said Hyundai recommends QS. She wanted me to know so as no issues if a warranty claim happened. Is this crap true?