I use ring xenon ultima have done for a while they seem to be pretty good ,supposed to give 120% more light on road .
The % brightness increase is very misleading. There is a maximum allowable light output from head lamp bulbs. From memory an E marked H7 bulb output is limited to 1500 lumens + or - 10% at 13.4 Volts. This would give a maximum legal output of 1650 lumens at 13.4 volts. These high performance bulbs simply output close to the 1650 lumen end of the scale. Additionally they generally have smaller filiments. This gives a tighter focus in the reflector, and so longer range. However this extra range is only any use if the headlamp is adjusted to use it. The claimed % increase is in comparison to an aged, standard halogen, not necessarily a new halogen bulb. All incandescent bulbs age over time, reducing the light output.
If more light is needed, there are a few improvements available. So are completely legal, some less so and one is completely illegal.
First legal improvement is to change the bulbs to better quality replacements. Those listed above will work and are much of a muchness. I like Osram Night Breakers but Alite +120, sold as Ring +120 are good. Philips Vision Extreme are good too.
To improve on these, you need to increase the voltage delivered to the bulbs them selves. This means adding relays and improved wiring. This reduces voltage drop at the filiments, driving them harder and so brighter.
Moving on from this, things get less legal. Most bulb manufacturers make higher powered versions of standard bulbs. These are considerably brighter than those legal high performance bulbs. For instance an Osram Rallye H7 pumps out 2100 lumens at 13.2 volts, up over 500 lumens. However because it's a 65 Watt bulb, it's not E marked therefore not legally allowed on the road. However because it provides a light that looks standard, it would likely not be noticed by the Mot tester.
The next improvement is completely illegal and likely to be noticed by everyone. This is the aftermarket HID conversation. These aren't to be recommend and they don't actually provide better a light. The burner is much to large for a standard reflector. This gives a huge amount of light leakage out of the lamp, mostly in a direction not intended by the reflector. This gives very high lumen levels but little of it goes where you want on the road. Also the Mot tester will fail them and they are easily spotted by the police. So in my opinion, these HID conversations are out. Additional to the light leakage, HIDs should be self leveling and have headlamp washing.
Hopefully some of this will help.
