ERD50
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
I would not assume "smart" oil minders abound. According to my BIL, who is a mechanic, they just use miles. I checked the Sienna forum, and it sounded like a dumb minder. My goal was to see how/if there was a way to tell the minder you used synthetic, but, alas, no.
I specifically looked in to the GM system, and it clearly states it is a combo of revolutions and engine temperature.
I found this, and it does say the Toyota Sienna (at least 2016) is a "miles only" measure.
https://www.yourmechanic.com/articl...a-service-indicator-lights-by-brent-minderler
I'm surprised Toyota would be that far behind. I searched "Ford Oil minder what does it measure" and the first hit says it monitors conditions, same with "Honda". But Hyundai and Volkswagen seemed to be miles only as well.
Yep, "it depends".
-ERD50