ive got a 1999 cavalier z24 and the guy at Autozone told me that the engine took 10W-30 synthetic. now i know im in a cobalt forum, but i figure you guys could help me out. i bought regular 10W-30 because for someone my age, synthetic is pretty damn expensive. know i want to know if there would be that much of a difference in performance if i put synthetic oil in it. would i get more power? would i get a smoother ride? will it prevent wear and tear better than regular?