I haven't ahd any problems in my Xterra. Dealer knows I'm using also and although they say it's unnecessary, there's nothing worng with it. I've always used Synthetics.
Usually the only time there is a problem is if the engine is old when you switch. Then, the synthetic clears out all the sludge that is creating false seals and you get leaks.
Never heard of head gasket problems. Where did you hear this? I use mobil 1 BTW. http://forums.freshalloy.com/forum/images/icons/smile.gif
Charles
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by 99ESMAX:
I recently heard that synthetic oil will ruin cylinder head gaskets. Anyone heard of this? I'm still wondering how that could be. Comments highly appreciated. http://forums.freshalloy.com/forum/images/icons/smile.gif<HR></BLOCKQUOTE>