Well I have had my Stongards on my fogs for quite some time. With no problem. I had the stock 55 watt bulbs in there. Well I put in the Piaa bulbs wich are also 55 watt bulbs. Now I have a brown spot in the center of the fogs were the stone guards have changed color. I will say the Piaa bulbs are much hotter than the stock bulbs. But they are also brighter. I am posting this for the help of others. I will call Piaa and stonguard today to see if I can find a solution. Bob