Gibbo205 said:
My questions are:-
1. What oil grade is best for my engine, taking into account the above, 0W-40, 5W-40, 10W-40 or something else?
2. Is the cooler thermostat a worthwhile addition?
I can see GT4's point on a thinner oil when cold will help lubricate things quicker from cold, but at the same time the thinner oil from cold could put more wear on the IMS bearing or thats at least my logical way of looking at it, can I have your feedback on this and why a 5W-40 or 10W-40 may be better for the IMS bearing than say a 0W-40.
Is the thermostat a proven must have, yes or no? Any downfalls to having it?
1) 0w40, its thin and quick (when cold), everything else is the same. The IMS bearing is a red-herring, the bearing is intentionally sealed, and if it still is, then the oil grade is irrelveant.
If it isn't, I'd want the thinnest oil with the best chance to penetrate, wash and re-lubricate (after all, pulling the seal and fully opening it is the only true way of sorting it using the original ballraces), so do the next best thing and use the most penetrative oil knoww to man (that's sort of a joke), even Porsche can't keep 0w40 in their pants.
2) Oh yes, forget the combination of bad placement and EU based emissions mandates, drop the temp and get better performance/power AND better reliability. No downsides.
Just as an aside, that first question (in oil grade terms) was EXACTLY what this post was about. Not bearings.
If they are still as Porsche intended, and most should be (certainly they will be early in their lives), then oil grade will make not a jot of difference.
They are isolated from the rest of the engine/sump - ie there is NO intentionally ongoing lubrication to the bearings (for good or bad). They are supposed to be sealed for life.