Changing Your Headlight Bulbs – A Guide to the Most Commonly Asked Car Bulb Questions


If you are looking to buy, replace or even upgrade your headlight bulbs there seems to be an immense amount of advice available. Typically the amount of information that is passed down through word of mouth can be confusing and so listed below are some of these most commonly asked questions and answers.

Should I buy and replace headlight bulbs in pairs?

Yes. This makes good common sense advice for two reasons. Firstly if one of your bulbs has blown it is very likely that the other one will go fairly soon, so if you have taken the effort of changing one bulb you might as well change the other whilst your at it, and then you will not have to repeat the process for a considerable time.

The other reason for changing car bulbs in pairs is because as a bulb gets towards the end of its life its light performance is not at its optimum level and so installing one brand new headlight bulb whilst leaving the other old bulb in place will cause a light imbalance, meaning you are not getting the best light performance from your headlight bulbs.

Can I touch the glass when changing the headlight bulbs?

No. No matter how clean your hands are, when you touch the glass you will leave a residue of some of your skins natural oils. When the headlight bulb is illuminated this oil creates a hot spot on the glass and can lead to the bulb failing much earlier than expected.

Top car bulb manufacturers now use toughened quartz glass in their bulbs and so this hotspot issue is not such a factor as it used to be. However it is still good practice to wear latex gloves when handling headlight bulbs to ensure you get the best service life from them.

My car has plastic headlight lenses, does it matter which headlight bulbs I buy?

Yes. If you install headlight bulbs that do not have special UV filtered glass it will very quickly, discolour and eventually damage the plastic lenses. Therefore if you do have plastic lenses on your vehicle make sure the headlight bulbs you buy have special UV cut glass, this will normally be labeled clearly on the packaging.

If I want brighter headlights on the road can I fit high wattage headlight bulbs?

No. Whilst high wattage headlight bulbs can be over twice as bright as standard bulbs, they are not legal on public roads. This is because the incredible bright light they produce can easily temporarily blind on coming drivers.

If you are looking to improve your headlights, you should install upgrade headlight xenon bulbs, these are identical to your existing bulbs but are filled with xenon gas and so emit up to 90% more light, and best of all they are completely road legal.

Is the owner’s manual the best way to find out what headlight auto bulbs are fitted to my vehicles?

Yes and No. Normally the owner’s manual will give you accurate information about which type of bulbs you have fitted to your vehicle and their location. However during a production run, vehicle manufacturers do sometimes change the specification, design or parts supplier and so the subsequent bulbs used may differ from the original manual.

Therefore the best way to find out which type of bulbs have been fitted to your vehicle is to remove them and check it visually. Normally the bulb type is printed on the bulbs base.

Buying and replacing your headlight bulbs should normally be a straightforward job, however as is the case with most technical items, being armed with the right information will help you make the decision easier. Fitting the right headlight bulbs, correctly will not only save you money in the long run, but also make night driving safer and less stressful.


Source by Jo Alexander

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