its a 97 chevrolet suburban k1500. got it second hand a few weeks ago. i already replaced it with oem fuel filter, oem oil filter and mobil1 0w-40 fully synthetic oil. ive been using this kind of oil for years now on my f-150. the suburban and the f150 specifies 5w-30 oil. i guess the 0winter grade is neglible in our kind of climate. engine performance is the same, fuel consumption is the same, no smoke color noticeable on the tail pipe. it works perfectly fine.