Originally Posted By: Nick R
I believe this has been discussed at some point, I can't remember.
Ah, here. This was in the Pennzoil Ultra Q&A. I think it should answer your question nicely.
Quote:
11. Are the base stocks group III, IV, or V?
Pennzoil Ultra™ is blended with Group III base stocks. These give superior solvency performance to Group IV base stocks, which we believe aids our aim to provide oil that delivers as close to “Factory Clean”. Rather than focus on any single component in the formulation, we focus on the end product.
Thanks Nick, this points me in the right direction.