Pennzoil PureBase used in High Millage Formula?

[94MaxGXE]

Hi All,
Do you guys think the High Millage oils use the same base stock as there regular oil formula?
Pennzoil quart bottle says PureBase on it, Pennz High Millage does not. If you look at the product dat sheets form Pennz web site, the HM fromula says nothing about PureBase, or GF-2/3 or Ford specs.
I would think that if Pennz were using PureBase for there HM formula, it would be stated on the bottle and/or the product data sheet.
What do you think?
Take Care......

 

[timzak]

I'd be curious to know as well...

 

[Patman]

I believe that all of the high mileage oils use a base oil which contains about 10% esters in it, so it's different than their conventional counterparts.