Originally Posted By: Shannow
Originally Posted By: Gokhan
Synthetic is a result of ACEA's NOACK spec. Since 15W-xx has such a thick base oil, its NOACK is low even with Group II; so, it doesn't need to be synthetic.
It's the same with GM dexos. GM dexos oils end up being synthetic because of the NOACK spec, not because dexos (or ACEA) explicitly specify synthetic (they don't).
API puts it best: “Synthetic” is a marketing term, not a technical term.
So 7-11 5W30 must be a synthetic ?
http://www.pqiadata.org/7Eleven5W30.html
So, what does that prove? You found one 5W-xx oil sold as conventional out of dozens that has Group III NOACK.
Recent batches of PYB showed very low NOACKs, as low as 6%. That's because they are actually synthetic (surplus GTL). They are marketed as conventional despite legally qualifying as synthetic, which is API's point.
API allows Group III to be substituted for Group II without retesting and blenders do that when they have surplus Group III.
Originally Posted By: Gokhan
Synthetic is a result of ACEA's NOACK spec. Since 15W-xx has such a thick base oil, its NOACK is low even with Group II; so, it doesn't need to be synthetic.
It's the same with GM dexos. GM dexos oils end up being synthetic because of the NOACK spec, not because dexos (or ACEA) explicitly specify synthetic (they don't).
API puts it best: “Synthetic” is a marketing term, not a technical term.
So 7-11 5W30 must be a synthetic ?
http://www.pqiadata.org/7Eleven5W30.html
So, what does that prove? You found one 5W-xx oil sold as conventional out of dozens that has Group III NOACK.
Recent batches of PYB showed very low NOACKs, as low as 6%. That's because they are actually synthetic (surplus GTL). They are marketed as conventional despite legally qualifying as synthetic, which is API's point.
API allows Group III to be substituted for Group II without retesting and blenders do that when they have surplus Group III.