I plan to use slightly thicker PU 5W20 in my S2000 which spec'ed for 10W30, also the lowest temp my car may see is no less than 45-50F so the low VI is not a real concern.
Also, I may replace 1 quart with M1 0W40 to make the mix a thick xW20 and a little closer to xW30.
I could not say no to $2.50/qt or $10.50 5-qt jug of PU API SN that my WM had on clearance shelf, and the $25 warranty rebate.