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”?