there it was. A full shelf, 25 bottles deep, red label german castrol. no yellow 0w-30 in sight! in schaumburg, (45 min from chicago) so, how thick is this stuff compared to mobil 1 10w-30 and 0w-40? would it be wise for me to stock up, do you think it will be obsolete soon? price is 4.99. I need pros and cons of buying the oil and stocking up.