Here is a interesting story.I went to Canadian Tire to get a Mobil 1 Extended Performance oil filter and their oil filter guide is missing pages for what make and year so this guy behind the counter said to me is this your first time putting synthetic in your car and i said yes..he said once you go from conventional to synthetic you cant turn back..lol i said realy.I know this is a myth but what do you think?Any who im sticking to synthetic for the life of the car and i find it cheaper in the long run so that was my choice not his