Obviously, I know this could certainly pose warranty issues, but - if changed with a proper OCI, how bad could it really be? I ask because where I work (national auto parts chain) people buy the cheapest stuff to put in their new BMW's, turbo VW's, etc. all day long. Personally, I don't see a major issue, as long as it's a proper grade and it's being changed in a reasonable amount of time, for your average joe streetcar driver. They do enough stupid things to their cars that make me not want to be a 2nd/3rd owner as it is.