wth... sell things here pulak..
anywayz, if your rims are lighter by 5kg a piece, that is a HUGE difference. You can't measure simply by its dead weight... as in putting it on the weighing scale to see how light it is... of course, it reduces the overall weight of the car definitely...
but most importantly, the lesser the weight of the rims, it takes lesser energy to rotate the wheels... which in turn, less fuel needed to get up to speed... better FC and better performance.... it is very very significant. That's why lightweight japan rims are damn expensive and quite hard to come by... :)