Question for you four stroke guys

[cterrebonne]

Originally Posted by wpearch

the reason the the OEM don't like synthetic oil is it works to well a new or rebuilt engine needs to wear in
at first synthetic won't let it

on some engines....as others dont. amg, srt, svo and the other factory performance subsidiaries all ship their engines with full syn and most use mobil 1. jag recomends castrol probablt because its a BP company but that is another topic. by todays engineering and machining standards of you can't cut a bore precise enough not to need to worry about break in, then you shouldnt make engines.