I'm thinking of purchase a corvette C5 sometime in the next few months. In this engine(LS1), chevrolet recommends/demands? Mobil 1 5w-30. I live in sweden and the only Mobil 1 i can buy locally is 5w-50 and 0w-40. I guess I can order home the 5w-30, but i was wondering if the two Mobil 1 I can purchase locally will work just as fine(or even better)? The car is only intended to be used in the summer. Outside temperature range: max 30C (86F) min 5C (41F) Any suggestions?