32.774 pages, minumum.
Ahem.
Anyway, Toyota told me the same thing in 2016 with my Camry. I've no doubt the full synthetic oils are better. I've also no doubt that Toyota & the dealers would like to save $. My gut told me they're betting that they can get the cars to the end of the factory warranty with 10K oil changes, and that's the end of what they have to stand behind.
You'll no doubt get lots of advice of what intervals to use. You're smart enough to know that highway miles are way easier on a car than city driving, and that short trips are hard on oil, especially in cold weather. Perhaps your Highlander has a GDI engine, and you're leery that might dilute the oil, so you go more conservatively on the OCI's. You could eyeball it. You could send samples of every batch to Blackstone for analysis. In the end, you'll pick a point on the spectrum where you feel most comfortable. And you'll be exactly right - for you.
After discussing it with my mechanic of 27 years, I settled on 7,500 mile intervals, paying for it myself at the mechanic when Toyota's "free maintenance" coupons wouldn't. I'll never know if I've been throwing $ away, but I figure the extra cost aint breaking me, and the peace of mind feels like a bargain.
Good Luck,
FC
