the general numbers you will find floating out there is that a 35watt HID bulb puts out about 3 times as much usable light as a 55watt halogen. (i don't know that to be true) and there are 50watt HID's for sale now. I purchased the 35watt, because as far as I know, no US vehicles ever came with anything more - I also chose the 4300k color, because that is also what comes stock. There are a few vehicles that come with 5000k, but they are too blue in my opinion. White is easier on the eyes anyways. I have problems with night vision, and the halogens just weren't cutting it - even though they may also be rated at 4300/4500k - halogens are significantly more "yellow" than pure-white HID's. The pure white (for me) means I can actually see the road and objects.

it is for most, a "cosmetic mod". For off-roading, I think you would probably also want hella h4's mounted either on the roof or front grill as flood lights - because you wouldn't be worried about blinding anyone. HID's in projector housing are focused and aim-able, probably not all that useful when you and your vehicle are at a 45 degree angle (up or down). <img src="/forums/images/graemlins/wink.gif" alt="" />