AFter reading a bit here about Chevron, I went to their spec sheets. I was floored at the specs for their straight weight oils. I know most here say that straight weights have no place anymore, but check this out:
These look like some serious (and inexpensive) oils for the hot summer climates. I bet that straight 40 could qualify as a 20W40 if they wanted. Heck, I would feel save with the 30wt in my car for a Dallas winter. After all, my service manual says I could run a 20w40 when temps are 20+ F.code:
10w30 10w40 20w50 30 40
Visc@40C 73.5 104 176 82 128
Visc@100C 10.8 14.8 19.0 10.3 14.0