Comparing the high mileage motor oils

[Mystic]

Does anybody know how the various high mileage motor oils compare? Valvoline, Castrol, Pennzoil, and I believe Quaker State all have these high mileage oils. There may be others as well-these are the ones I have heard about.

And how do the high mileage oils compare to their conventional counterparts?

 

[Ballbearing]

I think they are usually towards the high end of their viscosity class as in a high xw-30 or 40 weight,with a seal swell additive.Not sure that there,s much else thats different.