Originally Posted by semtex

The Ester oil thing. Ester does matter for wear, IMO. The thing about Ester is that it bonds to metal, thereby increasing the lubricity of the components especially at startup. My understanding is that Mobil1 Extended Performance has ester, but the regular stuff doesn't. I've also been told by my tuning mechanic that I shouldn't switch from conventional oil to synthetic until after at least 5000 miles. (I'm not necessarily vouching for his position on this, I'm just telling you what I've been told. You can draw your own conclusions.)