Based on on the treads I have read on this Chevron Delo 400 15w-40 is plentiful and readily available at a good price in my area.
I recently did a bunch of engine work chasing down oil in my intake turns out the spark plug seals tubes were the culprit. I wanted to verify wasn't blowing a bunch of oil past my valve stem seals before I switch to a heavier oil.
I live inland of the bay area of California so it's a very warm climate mild winter.