Comparing the high mileage motor oils

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8,467
Location
Colorado
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?
 
Messages
18
Location
Wellington
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. [I dont know]
 
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