I have a 16 Tundra and a 15 Sienna that Toyota recommends 0w20 oil for except for in “severe conditions,” which I understand to be off road, towing and high speeds, in which case 5w30 is recommended but only if the following oil change is 0w20.
Where I live the interstate speed limit is 80, and I drive the Tundra off road with some regularity. We also have coldish winters (-10F). I’ve decided that 0w30 is a compromise between start up lubrication and at full temp film strength. Is this wrong headed of me? What exactly classifies as “high speed”?
It’s my understanding that the “at the following oil change” language is in the manual to satisfy CAFE requirements/MPG purposes and not for any other real reason.
The ancient 2.7L engine in my Tacoma originally called for 5W-30 in the US but was back-spec’d to 0W-20 several years ago. I use 5W-30 in it since it is a little quieter/smoother/less clattery with it and because our Yaris takes 5W-30 (I buy the boxes of synthetic Kirkland oil at Costco).
I’ve had the same thought as you to use 0W-30 but haven’t switched since it’s a little pricier. (I use the Costco synthetic oil that is $30.99 for 10 quarts … truck takes about 6 quarts, car takes about 4 - it’s perfect).
Anyway, what I did was to find the Australian owner’s manual (not subject to CAFE) for a vehicle that uses the same engine (in my case, the Hilux) which says that 0W-20 is preferred but that anything up to 10W-30 can be used. Look here: https://toyotamanuals.com.au
Hilux page for the 2.7L
https://i.imgur.com/Mxh4ErX.pngHere is the owner’s manual for a 2016 Australian V6 Highlander (called Kluger down there). They say 5W-30 is the thinnest allowed and that you can use up to 15W-40 (!)
https://i.imgur.com/0CVv9Cl.pngAwesome, this is exactly what I was looking for. Thank you.