When it comes to car headlight bulbs each make and model of car has to choose one of two main options. Either have two separate headlight bulbs, one for the dip beam and one for the main beam, or have one special headlight bulb that does both the dip & main.
When they have both the dip and main together the bulb has to have 2 filaments, (see picture) and one of them is lit all the time the bulbs are on (dip beam).
The second filament will only light up when you activate the main beam.
The most common type of headlamp bulb with two filaments in is a H4 (472) bulb which is easy to recognise when you take it out as it has a 3 pin connection.
All the following car makers use the H4 types of bulbs for their twin element type bulbs, Vauxhall, Ford, VW, Toyota, Jaguar, Fiat, Nissan, Honda, and Renault. But don’t forget your car may not have the twin element type.
The cars that go for the two separate bulb option usually use a H1 (448) headlight bulb for the main beam and a H7 (499) for the dip beam.
The H1 shown below has just a single pin connection and the H7 has a two pin connection.
The H4 headlight bulb is virtually the only 2 filament option open to the worlds major car manufacturers, but there are lots of other types of single filament headlight bulbs available besides the H1 and H7.
Although those two types are probably in 90% of single filament head lamps throughout Europe today, there are a lot of other types that your car might have.
We have listed some of the other types on this page.
If you'd like to know which headlights fit your car please use our Make and Model Search for Bulbs here or phone us free on 0800 019 6459.
Here is a Brief History of Car Headlight Bulbs.
The first cars to have headlamps (these were not electric lamps) were way back in 1880. The first electrically run headlights were seen on an electric powered car in 1898, made in the USA.
Some cars started to offer them as standard equipment from 1904 but it was Cadillac who introduced the electrical ignition and lighting system in 1912 that really started off lights on cars as we know them today.
Dipped or low beam headlights came out in 1915 but they were crude examples. Again it was Cadillac that invented the first headlights that could be dipped merely by using a lever inside the car in 1917.
In 1927, the foot-operated dimmer switch was introduced and became standard for many years.
Modern day headlights are required to produce a low and a high beam. Low beam headlights are for use on one side of the road. In the UK our dip beams are set to show light on the centre and left hand side of the road so as not to dazzle oncoming vehicles.
Obviously if you do drive through Europe, France, Spain for example, then you will legally be required to use headlamp adaptors to avoid dazzling oncoming traffic. See Headlamp Adaptors here.
The first car to be fitted with Xenon headlights was the BMW 7 Series in 1991. Even to this day most cars are still fitted with standard Halogen headlamps. Xenons are still considered to be a luxury.
Xenons burn brighter due to the gas enabling them to get far more light from the same wattage/voltage. It is worth remembering though that if something burns brighter it is often short lived. Xenon's such as the Osram Nightbreakers only last half the time of a standard headlight bulb and very often even less than that.
We at Click Parts sell a full range of xenon upgrade headlight bulbs here including the new Philips Eco Vision headlight bulbs. These have addressed the problems of longevity.These new bulbs consume 20% less energy, generate 10% more light and last twice as long as standard head light bulbs.