always check the gap on your plugs. i just put some new plugs in at my last oil change, and my car has sounded funny ever since got some new plugs because i knew that was the only thing that i had changed. set the gap for the firdst time to .051 or so. took out the old ones checked them and the gap was like .041. all of a sudden my car has better top end. oh well, oh, and also found some 93 octane in town for cheaper than others sell 91. not that it will help me much, if any. -Josh