100w Headlamp bulbs

My headlamp connectors melted, and that was with standard55w bulbs.

Cheap 'xenon' bulbs are exactly that - cheap bulbs, although they are tinted blue. :yesnod:

If you want improved headlamp output, Buy some Osram Nightbreakers. If your reflectors are still good they really improve your headlights.
If your reflectors are dull the Nightbreakers will help 'a bit' But only new headlamps will help, or rechroming the reflectors.

100 w bulbs are an bad idea end of

Don't fit 100w bulbs.

You will melt the wiring, and if your reflectors were ok, they won't be for long. It will bring on reflector oxidisation.

As David suggests, OSRAM Nightbreakers are the way to go. Not cheap but sooo worth it.

Good morning, said the devils advocate ..

My headlamp connectors melted, and that was with standard bulbs.

With 100w bulbs or 55w bulbs David? I don't really know what the extra 45watts is supposed to do. Produce more light power I suppose? Any sparkies in the house?

Cheap 'xenon' bulbs are exactly that - cheap bulbs.

Cheap bulbs aren't necessarily 'nasty' bulbs and some aren't necessarily better or worse than more costly bulbs. I've had some good cheap bulbs off fleabay in the past. Fortunately, they've all been good. However, if they were no good then it would have been a worthwhile gamble for the price paid.

If you don't want to do the full HID upgrade... Upgrading from yellow to white bulbs has some impact on how your car looks and presents on the road.

If your reflectors are dull the Nightbreakers will help 'a bit' But only new headlamps will help, or rechroming the reflectors.

Again it's down to costs. Replacing old reflectors or rechroming costs an arm and a leg compared to swapping out bulbs from yellow to white (but not blue tinted bulbs). I've done that upgrade on my last two cars, the TF and clio, and the difference was impressive. You may not see further but you can be seen more easily in my humble opinion.

Leigh Ping wrote: Good morning, said the devils advocate ..

My headlamp connectors melted, and that was with standard bulbs.

With 100w bulbs or 55w bulbs David? I don't really know what the extra 45watts is supposed to do. Produce more light power I suppose? Any sparkies in the house?

Halogen light bulbs are about 2.6% efficient. (2.6% of the energy is turned into light and the rest is heat, so there is a lot more heat for not that much more light. Coupled to that the lighting circuit has cabling which is designed for 55w with a safety margin of maybe 10w (probably more like 5). So you're looking at a overloaded cables, which also have a tendancy to get hot.

Cheap 'xenon' bulbs are exactly that - cheap bulbs.

Cheap bulbs aren't necessarily 'nasty' bulbs and some aren't necessarily better or worse than more costly bulbs. I've had some good cheap bulbs off fleabay in the past. Fortunately, they've all been good. However, if they were no good then it would have been a worthwhile gamble for the price paid.

If you don't want to do the full HID upgrade... Upgrading from yellow to white bulbs has some impact on how your car looks and presents on the road.

To be honest I'm with David, there would be a difference with the more expensive nightbreakers, not only in being seen, but also in the more important aspect of being able to see.

If your reflectors are dull the Nightbreakers will help 'a bit' But only new headlamps will help, or rechroming the reflectors.

Again it's down to costs. Replacing old reflectors or rechroming costs an arm and a leg compared to swapping out bulbs from yellow to white (but not blue tinted bulbs). I've done that upgrade on my last two cars, the TF and clio, and the difference was impressive. You may not see further but you can be seen more easily in my humble opinion.

On the TF and Clio, you don't suffer from reflector oxidisation. It is a serious problem on the F, which can reduce the lights to being useless (even with good quality bulbs).

The reflector is supposed to focus the light, if dulled it blocks most of the light and scatters the remainder (not good for oncoming traffic and certainly no good at all for you). Swapping the bulbs does nothing to change this. The only solution is either a rechrome or lamp replacement. No ifs or buts.

100W lamps are illegal for road use in this country. The extra 45W also produces nearly twice as much heat and draws a lot more current.

In a balanced load Amps = Watts/Voltage.

So, in a 12V system a pair of 55W lamps draw nearly 9A. A pair of 100W lamps draw around 17A.

This alone is enough to overload your electrical system and will cause degradation of wiring and components. It won't be instant, but things will melt and fail after a while, possibly causing a short circuit and fire.

The heat given out by 100W lamps is enough to distort and discolour plastic lenses and the silverlink of the reflector around. It will cause components, including the lamp holder to become brittle.

Sorry, as an Electrical Enginner, couldn't let this one go.

Headlights are usually used when the engine is running. So the battery applied voltage is around 14.4 Volts. Due to alternator input.
So Ohms Law gives 200/14.4. Just under 14 Amps.
55W x 2 gives just over 7.5 Amps.
So Clive's figures are correct when engine off. If you are dopey enough to have your headlamps on when the engine ain't running.
The cables will probably still overheat with 100 W lamps, but depends on the csa of the cable. May be ok.
Just saying.

I used to run 100W high beam bulbs on the rally car, never had a problem. Also ran some big mother Cibie long range driving lights again without a problem. Mind you it was a 1989 Skoda so probably had better wiring than an MGF :coat:

John and Sue wrote: Sorry, as an Electrical Enginner, couldn't let this one go.

Headlights are usually used when the engine is running. So the battery applied voltage is around 14.4 Volts. Due to alternator input.
So Ohms Law gives 200/14.4. Just under 14 Amps.
55W x 2 gives just over 7.5 Amps.
So Clive's figures are correct when engine off. If you are dopey enough to have your headlamps on when the engine ain't running.
The cables will probably still overheat with 100 W lamps, but depends on the csa of the cable. May be ok.
Just saying.

Really?

It was only a rule of thumb.

But if we are going this route then maybe you should have mentioned effects of temperature and worked out the resistance of the cable lengths. Maybe you should take into account also that you design a circuit for the worst operating scenario, so the driver could sit with headlights on and engine off, which would be around 12 - 12.8V

Rich in Vancouver wrote: I used to run 100W high beam bulbs on the rally car, never had a problem. Also ran some big mother Cibie long range driving lights again without a problem. Mind you it was a 1989 Skoda so probably had better wiring than an MGF :coat:

I did similar on my Ford Sierra and the light control stalk burned out, at night, with 100 miles left on my journey. The only thing that worked was flash, so did the rest of the journey with my hand on the flash. Obviously went black ops when a car was coming the other way, but it was 3am. Still not sure the stalk wasn't a coincidence, but hey, you never know.

David Aiketgate wrote: My headlamp connectors melted, and that was with standard55w bulbs.

This is usually due to a loose connection. Maybe the base of the lamp wasn't quite to the design spec. What results is the connection will move under vibration, such as driving, causing arcing between the contacts. This sort of arcing can cause localised heating in the same way as arc welding, which eventually will erode or melt the connection.