hey guys, i bought a 98 civic with 165k, used dino 5-30 for the first few oil changes, would it be ok to now go with a synthetic or a hi mileage oil from here on out? the car is leaking no oil or burning any from what i can tell so far.(keep ur fingers crossed) have read around and some people are saying if your car has hi miles just stick to the dino, please help me out, thanks !