Originally Posted by paoester
Seals are usually silicone rubber these days, about widespread post-2002 or so, meaning any extra seal conditioners (high mileage oil's main thing) wouldn't have any effect.
Viton (flouropolymer), polyacrylate, silicone, or maybe nylon are used for valve stem seals. Oil pan gaskets are silicone usually.
I don't think High Mileage really does much any more. Let the oil specs any oil meets tell you how well it will perform.
https://www.youtube.com/watch?v=m7F9AwUUJVE&vl=en is where they go through some
marketing ideas they had back in the 90's, for older cars back then.
From the 27.00 point to about 29:10 in
https://www.youtube.com/watch?v=FXqkOZAkXZw a Vavloline engineer mentions
that Valvoline High Mileage oil has
extra seal conditioners (the main difference) but it also has a small amount of ashless anti-wear compounds, which I think is meaningless since all synthetic oils that pass dexos1 or VW 508 for example have good anti-wear performance already. She also says there are more dispersants to prevent deposits, but again, WPD limits are dictated by dexos1 or other high syn oil specs already.
Once again you put out false info. Why?