[jtbayly]

Unless they know it will last 150k miles and don't care beyond that. Or put more cynically, have set the window for artificial obsolescence of their vehicles early enough to goose sales, but late enough that their reputation and liability don't take a hit.

[prepend]

That’s why I mentioned class action suites. If a manufacturer did that, it would be a dream for a law firm as it would be pretty easy to show the damage of doing 5 oil changes over 150k miles as recommended (vs 15 or 30 or whatever). Of course consumers would get $5 or something small, but a law firm would get millions that would be paid by the manufacturer.

Again, hard to know. But when the manufacturers have something to lose from being wrong and random mechanic who sells oils changes doesn’t, it makes it easier to man vehicle maintenance.