i NEVER seen a rule about how much "synthetic" usually group III is required to be legally labeled as such + seeing a full "synthetic' group III is not much more i call it a no-brainer!! girlfriends 13 Malibu 2.5L LS was drinking the semi-syn dexos I 5-20 but a switch to 10-30 Mobil I cured that. a 10W is good enough in PA when its group III prolly samo in NJ. a look at Noack #'s show the 10-30 a lot BETTER!!