Originally Posted By: 28gauge
Keep in mind that I live in Tucson, AZ. 105 degrees (and higher) is quite common for many months. Early morning winter might see a freeze like 30 degrees, but quickly move up to the 50's and 60's in the afternoon. In my last 2012 4Runner I went by the book with the 0W20. Traded it in with 38K miles without any issues. My 2017 has 7K miles on it now and I think I'm going to the M1 0W30 going forward 12 months year. While I don't tow or do much off-roading, we do travel to the White Mountains which involves a bit of climbing through elevations. Again, I consider the weather alone severe condition.
From +30F to +105F sounds perfect for something like M1 10W30. Less shear, lower Noack volatility, less polymer VII load. I agree with selecting an oil based on your climate and application, but I would extend that to include the cold starting winter (W) rating as well as the operational temperature viscosity.
I live in a very similar climate (ignoring humidity) a 10W or 15W oil is more than ample cold starting ability. Just throwing it out there for your consideration