Uprated H4 Headlamp Bulbs

[Tim Ray]

Hello
Has anybody had experience of fitting uprated headlamp bulbs.I've seen some 100/90 Watt bulbs advertised on e-bay and they claim to replace any H4 halogen bulbs. Physically, very possibly but I need to be convinced electrically, as it's a significant increase from the 60/55 Watt ones I have currently fitted to my Series 2 Fulvia Coupé. .
I like the idea of having more powerful lights but not at the possible risk of burnt cables and/or damage to switches or relays.
Any thoughts gratefully received.
Regards
Tim

[Zagato]

If you are worried about the wiring with the higher wattage you can buy 60/55's which give 50% more light ...
I haven't got a part number for them to hand but will try and find one
I bought some recently, fitted them but haven't tried them in the dark yet

Richard

[Zagato]

Tim

I purchased mine from my local Vauxhall dealer

The part number for the H4 is 93169038

I don't think many dealers keep them in stock but should be able to order them for you - should only take a couple of days for them to arrive
I can't remember how much they were ... so please check with them first before ordering

They also do an H7 bulb too

Hope this helps
Richard

[the.cern]

Tim, I read a very learned paper, can't remember where, but possibly on this forum, on the subject of bulb wattage, headlamp brightness and effectiveness. It fully explained in scientific terms how amps, volts, watts, resistance etc etc interact to produce the desired effect, ie light. Way beyond my A level physics !!!

The bottom line was that a higher wattage does not always lead to greater brightness and illumination, sometimes it can have the opposite effect.  Having read this I am convinced that the possible advantages that may be gained by changing to higher rated bulbs would be very limited and carry the risk, as you have identified, of damage to circuitry. I determined that standard bulbs was definitely the better option, although the bulb type identified by Richard seems to offer a good way forward, possibly something for nothing, but bulb life might be an issue. Richard, if this proves to be a problem please would you let us know.

Good luck,

                Andy

[fay66]

 Quite a few years ago I used to fit 100/80's to my Dedra's but at the time this was illegal.

Has the law changed or is it down to the technology?

Brian
8227

[richardgcs]

The question of headlight maximum wattage appears every now and again.There isnt and never has been a legal maximum(this is an Urban myth. Lights must not dazzle or cause discomfort to other road users.Check out construction and use.