what! rotational weight. think about it for a second. like on a bicycle. why do you want lighter wheels? less rotation weight, spins faster. easier to pull up. quicker speeds. faster acceleration. (pending on what kind of bike it is.) the less weight the car (or bicycle) has to push the easier it is for it to slow down then pick back up speed. you'd be surprised at how much lighter wheels make a difference. im rocking knock off rota torques. right at 18lbs a wheel. look good an hell of a lot lighter than stock. i immediately felt the difference in handling and acceleration. and as a major DD i wont buy some rays. or advans and why? cause id s*** a brick if i got a nick scratch or curb on them. sure, they are sick and nice to say well, i have some volks. but **** me if they were to get ****** from driving on them so much.