Modern Car Headlight Bulbs; Short Lived?

[Cleggy]

I frequent a couple of car-related forums and the subject of modern headlight bulbs failing after quite low mileage comes up all the time. Of course, in order to make them brighter, the manufacturers have pushed the operating temperatures "towards the limit".

As I understand it, the quality makers work on the basis that the voltage shown by the charging system peaks at 14.4V and I think I recall seeing the comment that filament temperature increases with V squared. I've seen suggestions that some alternators produce spikes.

This isn't a problem that I can honestly say that I've really suffered from, but its clear that it's a common problem and isn't specific to any make or model of car, so I find it quite curious. Has anyone got any profound insights on this one?

[Murphyv310]

Hi.
Most failures are on upgraded bulbs. Osram Nightbreakers are the worst, Philips Extreme don't come out well either.
Charging these days is controlled by the BCU and the aim is rightly for 13.8-14.4v. At the bulbs filament its likely to be 12.5-13v due to losses in the system.
Car bulbs used to be rated at 12v nominal +10% so 13.2v is within the normal rating, so the bulb should be fine in the vast majority of vehicles due to normal losses in wiring, relay contacts, fuses etc, canbus systems too have a small voltage drop.
Personally I'd blame poor quality bulbs than the vehicle.
Any alternator spikes which is unlikely will be damped by that great big capacitor called the battery

[Ed_Dinning]

Hi Gents, I guess there are a lot of bulb failures judging by the great number of vehicles on the road with lights out (how can you not notice that as a driver?) and with mis-aimed headlights.
This latter due to DIY'ers not certain of how to fit the bulb and happy that it is alight, even if not pointing in the correct direction.

Ed

[Murphyv310]

Hi Gents, I guess there are a lot of bulb failures judging by the great number of vehicles on the road with lights out (how can you not notice that as a driver?) and with mis-aimed headlights.
This latter due to DIY'ers not certain of how to fit the bulb and happy that it is alight, even if not pointing in the correct direction.

Ed

Hi Ed.
Some of the latest cars are a nightmare to replace bulbs, bumper removal, airboxes and all sorts, long gone are the days of a two minute bulb replacement.

[Terry]

I wonder how drivers get on in France these days? By law you must carry a set of replacement bulbs and, if the police stop you with a defective light, you are supposed to demonstrate that you can replace it at the roadside.

That won't work any more on many cars ...

[Murphyv310]

I wonder how drivers get on in France these days? By law you must carry a set of replacement bulbs and, if the police stop you with a defective light, you are supposed to demonstrate that you can replace it at the roadside.

That won't work any more on many cars ...

Too true Terry!
What cars are one of the worst to replace bulbs.................. Yes the French ones are at the top of the list

[AlanBeckett]

Some years ago my Mrs had a Smart For2 - the original one. The Offside Headlight Bulb failed and it was a nightmare. As far as I could tell the Nearside one was impossible as it had AirCon. I got them (Merc) to change it a the next Service, just as a precaution.

Alan

[Cleggy]

Hi.
Most failures are on upgraded bulbs. Osram Nightbreakers are the worst, Philips Extreme don't come out well either.

Personally I'd blame poor quality bulbs than the vehicle.

While I don't disagree, it does seem surprising that major suppliers like Osram and Philips allow themselves to be drawn down this path of making lamps which are just too bright to be durable.

Toyotas seem to be designed to give headlight grief. I reckon that I'll mess about for up to an hour to fit a bulb in my Celica and a friend with an Avensis says the bumper needs to come off and he pays the dealer to do it! Takes me about 2 minutes to change the bulbs on my 1970 Viva .

[boater sam]

Many modern cars run the headlamp bulbs dip and main filaments in series I think as "running" lights when side lights and ignition is on. My dear much love Hyundai coupe did this and yes, I had to replace the bulbs every 2 to 3 years, but they were 90/ 150 Watt night fright searchlight bulbs!

[ppppenguin]

Looks like you can now get LED headlight conversion kits.
https://www.superbrightleds.com/cat/led-...sion-kits/
One hopes they will have a longer life than conventional bulbs.

Presumably new cars will be increasingly fitted with LED headlights as standard. Seems a much better bet than thecomplex and dazzling xenon bulbs used on many high end cars. Other bulbs such as brake lights, indicators ought to have been LED as from a few years ago. I think my 2006 Golf has LEDs in most positions except the headlights.