I'm running CCC wide fenders and they are lighter, but exactly how much I couldn't tell you. If you're going for the wider fenders, it's really not important anyway, because unless you want to spend a whole lot of time and money to get custom metal widened fenders made (that will weigh substantiately more than stock), you really don't have any other option. Not to be flip, but they weigh what they weigh. If you really want to know contact the manufacturer and ask, they should be able to tell you. My car has all the bolt on metal replaced with fiberglass, and I estimate that it saved 150 or so lbs. A lot of that was in the bumpers though. (The late model bumpers were HEAVY!), The airdam, side panels, and whale tail kept it from being lighter.