Since I have a 2018 Jetta instead of a '19 Jetta, and the '18 Jetta recommends VW 502 00 and/or VW 504 00 approved oils, which viscosity grade? The owners manual said that it was filled with 0w30 or 5w30, but when I went to the auto parts shop, they said VW recommended 5w40 for the '18 Jetta with the 1.4t engine. Did I miss something? Was there a technical service bulletin issued by VW? I'm sure this topic was covered before since I'm new here on BITOG, and I read that the '19 Jetta now recommends VW 508 00/509 00 oil, which is not for the '18 Jetta. Any answers are appreciated. Thanks.