I took everything out of the bottom of the cargo area and checked the pressure in the spare, today. It was no easy task. The tow foam carriers were loaded with emergency supplies and tools. I have the extra top carpet provided to me by Southeast Toyota. To make it even more difficult, the jack and tool holder had also to be removed and the tire had to be removed and turned over to get to the valve stem. It's 79 degrees F outside, and my donut spare was inflated to 95 pounds that the factory. I guess they assumed that it will be several years, before I use the spare, if at all, and by that time, the air would have leaked to somewhere near the recommended inflation pressure of 60 pounds. I released some air to get it to 70 pounds, since it will be less in the winter. 90 pounds plus is the pressured need for my Class C trailer tires. I'll check the spare once a year from now on.
I think it's likely OK. I've noticed how miraculously spares seem to hold pressure, but given its thinner profile it certainly would need to have more pressure than regular tires to avoid running on the rims of the wheel.
