I put these in my high beams last week and it seems that the lights have a mind of there own. They seem to take a few seconds to warm up before they actually turn on. Then if I need to go to low beams when meeting oncoming traffic, then try to go back to high beams the bulbs wont even turn on. As far as light output they seem to light up everything but IMO there not as bright road wise as the stock bulbs. I'm probably going to try to send them back this week and get some Sylvania Ultras.