To be fair, the ad material reads like it says that but it doesn't. It says if you use synthetic oil and use your vehicle in heavy duty service it is the right filter. The Wix XP filter is their best filter and has synthetic filtering material (media). All the internals of the filter are their best. Based on its price I have to say it's a Best Buy. But there's nothing in it that would restrict it to synthetic oil, just as there is nothing about the lower line filters that would exclude them from use with synthetic oil.
R.
