yesterday i felt my 91 si was running a little rough, when checking the oil level, it did not reach the stick. i added two quatrs and that made the level almost full. (how come my oil light did not lite up?) so i started paying closer attention, and ive noticed a black shiney spray pattern on the ground or anything unlucky enough to be behind my car. from reading other threads im assuming its my piston rings. but ive learned what assuming can do, so im just running by you guys to be certain..