Originally Posted By: Shannow
No probs..
there's been a meme for a long time on the board that synthetics (like TGMO 0W20, or Mobil Racing 0W50 with it's 3.7HTHS) get their "0W" rating "by accident" as a result of their superior ingredients.
The 15W therefore strikes me as a bit odd, given that if it met 10W or 5W it must be labelled as such.
I do understand what you're staying here. I can't honestly recall ever having tried to make a full PAO 15W40 so you may well be right.
However if memory serves, a typical Euro Group I 15W40 might contain about 7-8% liquid OCP VII. By switching from Group I to PAO you're going to up the aggregate base oil VI from say 100 to 130 which is good, but 7-8% of VII represents a lot of VI to displace. My gut feel would be that a reasonably viscometrically tight full PAO 15W40 should be doable.
No probs..
there's been a meme for a long time on the board that synthetics (like TGMO 0W20, or Mobil Racing 0W50 with it's 3.7HTHS) get their "0W" rating "by accident" as a result of their superior ingredients.
The 15W therefore strikes me as a bit odd, given that if it met 10W or 5W it must be labelled as such.
I do understand what you're staying here. I can't honestly recall ever having tried to make a full PAO 15W40 so you may well be right.
However if memory serves, a typical Euro Group I 15W40 might contain about 7-8% liquid OCP VII. By switching from Group I to PAO you're going to up the aggregate base oil VI from say 100 to 130 which is good, but 7-8% of VII represents a lot of VI to displace. My gut feel would be that a reasonably viscometrically tight full PAO 15W40 should be doable.