Do the 55w ballasts use 35w bulbs and "over light" the bulbs? Thinking of going from 35 to 55 on my xenons, and is there much chance of the 55w ballasts being too hot to melt the xenon head lights?

I have 55w ballasts in my GB Xenons. I didn't look at the bulbs before fitting tbh.

They have given a very good light output (with 4300k rating) and have not caused any damage from excessive heat.

I'm running 35w bulbs off a 55w ballast. They said 35w was recommend, but 55w was fine for mine (Morimoto I think).

The higher w ballasts can change the colour outputs of bulbs too.

It will reduce the life of them

Might reduce the life of a lot more than the bulbs IMO. Could end up melting/discolouring/deforming plastics inside the headlight enclosure.

Cheaper HID bulbs tend to run hotter. 55w cheaper bulbs isn't goign to help that.