I have searched for years for some sort of list of VW oil specifications... Haven't found one and more importantly no one has been able to explain what the specs I do have (ie: 502 00, 503. 01, 505 00, 506....etc.) mean.... I'd love to know what the heck these numbers mean and which one/ones are most applicable to my 1999 Passat 1.8T. Oh I hope I've finally found the answers here.