Latest News:

autotechnician - serving the independent workshop - logo

Casting light over bulbs

By Mike Smith on January 24, 2020

With automotive bulbs possessing a vast array of designs, upgrade options and fitting complexities, Rob Marshall investigates these precision-made parts, including researching advice that you can impart to your customers.

As blown filament bulbs are reported to be the most common reason for MOT Test failure, it is fair to conclude that many drivers do not notice that they have been driving around for some time with a faulty lamp. While most customers will react to this often panic-purchase by instructing you to simply replace the bulb (which is not always straightforward), you might be missing-out on the opportunity not only to boost your income but also offer valuable extra services.


In order to spread the optimum amount of light onto the road, while not dazzling oncoming traffic/pedestrians, automotive bulbs must be made to extremely precise tolerances. This is one reason why replaceable halogen bulbs of all types are one of the few replacement parts that have to be Type Approved by law and wear an E-mark to signify compliance with ECE Regulation 37.

Yet, counterfeit, non-compliant bulbs are rife. Ring Automotive reports that such bulbs tend to be sourced typically from discounters, or via the Internet and not reputable retailers. Philips and its lighting subsidiary, Lumileds, has also highlighted this and is working hard to raise the profile of the dangerous fakes, most notably, through the BBC television series, ‘Fake Britain’. Reacting to more fake and counterfeit bulbs appearing on the market, Osram, Ring Automotive’s parent company, created the Osram Trust Tool in 2016, allowing consumers to verify authenticity of the bulbs they had purchased. Osram argues that fitting the fakes can lead to premature failures and poor light performance, with obvious safety implications. Yet, note especially that quality producers go beyond the bare minimum regulations; Ring is one such brand that puts its bulbs through extra tests that assess lifespan, vibration resistance and colour temperature testing at its own lighting laboratory, for example. This is why you should insist on supplying and fitting your own bulbs, despite your customer arguing that their online purchase might be cheaper.

When fitting new lamps, trust a supplier that includes comprehensive instructions, so that you install them correctly and legally. Take time to read them before starting work.

In cases where replacing bulbs attract relatively hefty labour bills, consider recommending a long-life bulb. The extra longevity might be achieved by reducing the filament temperature and, therefore, the performance. Yet, bulb technology is not that simple. Osram, for example, states that the extended lifespan of its ULTRA LIFE range is a result of a combination of a ‘massive’ filament, rare filling gas composition and higher gas pressure, which allows it to maintain the same light output as the company’s ORIGINAL range.

Consider also that, while original HID ‘xenon’ gas discharge headlight bulbs do not fail suddenly, like filament types, their performance drops considerably as they age. Ring Automotive told AT that, while its tests revealed that new HIDs get whiter and brighter as they ‘bed-in’, the brightness drops and the colour temperature changes from white to a yellow hue as they age beyond their peak. Both Ring Automotive and Osram, therefore, advise that HID headlight bulbs are replaced in pairs after three years. You might wish to pass this recommendation to a customer, especially if you receive a complaint about poor headlamp performance.

The option to fit additional lamps offers an extra opportunity. Daytime running lamps (DRL) lamps are popular sellers for certain models that pre-date 2011, when DRLs became mandatory on new cars. While our advice is that you supply and fit a DRL kit, note that the quality manufacturers will supply adequate fitting instructions, enabling you to comply with the fitting regulations and not mount the lamps incorrectly by accident. Both Ring Automotive and Osram highlight that they provide not only comprehensive fitting instructions with its DRL kits but also online videos that feature on their respective websites.


Should a customer request that you fit brighter bulbs to their headlamps specifically, query why. Are they trying to compensate for poor alignment, or even a deteriorated reflector? Either way, brighter bulbs are not the answer. Consider also passing-on the advice from the Association of Optometrists, which told AT:

“A brighter headlight can mean that drivers are able to detect road hazards, signage and pedestrians at greater distances. However, having a bright light in front of you does affect your ability to adapt to seeing in the dark – meaning that objects that aren’t directly illuminated for example, pedestrians on pavements or in mirrors, may be harder to see.”

Rear light with matrix OLED technology

Even so, many bulb companies have detected a profit opportunity and the market for ‘brighter’ bulbs has proliferated, along with the sometimes rather daft superheroesque marketing names. Philips highlighted that both its ‘XtremeVision G-Force’, or the ‘WhiteVision Ultra’, possess superior performance over a standard alternative because, while there tends to be a natural trade-off between performance and lifespan, the Philips bulbs possess higher pressures within the bulb and superior filament materials/ technology are employed. Meanwhile ‘NIGHT BREAKER LASER’ (along with its capitalised nomenclature) is Osram’s leading Performance upgrade, which the company states offers up to 150% more brightness on the road ahead, up to 150 metres longer beam and 20% whiter light, whereas its ‘NIGHT BREAKER SILVER’ offers up to 100% more brightness and a beam that is 130 metres longer. These percentage figures are compared to minimum ECE R112/R37 requirements, in case you were wondering…

If seeking to fit new LED lamps, they must be sealed and E-marked.

More importantly, all of these upgrade bulbs still comply with the legal requirements. Yet, a huge variety of bulbs have appeared on the market to convert halogen lamps into alternative light sources. These are not road legal. The most obvious of them were HID headlight bulb conversion kits that became so prolific that MOT Testers were used to police the existing law and fail any vehicle that was presented with them fitted. More recently, LED conversion bulbs have appeared for not only fitting into halogen headlights (these are not road legal for the same reasons as HID conversions) but also in side lamps and indicators.

You may be asked to supply and fit these bulbs by customers, who reason that, because new cars have LEDs fitted, why should their older models not be upgraded? The reason is that new cars have the LEDs and the internal reflectors designed so that they work together to comply with the relevant standards and are E-marked. To date, LED conversion bulbs do not work adequately with halogen lamp optics to comply with the relevant standards, which is why no road legal alternative is available at present.

Understandably, online marketplace sites are awash with LED conversion bulbs but we were surprised to find that established and respected bulb producers were also selling them for exterior lamp use, albeit with the caveat of ‘OffRoad Use Only’. We queried these companies about their responsibilities of introducing non-compliant bulbs into the British market, all of which responded that their packages state clearly that they are for off-road use but that they are not able to control their fitting and use. As the UK’s Road Traffic Act states that it is an offence to supply, fit, or use vehicle parts that do not comply with the required Construction and Use stipulations, we asked those bulb makers if they would cover the legal costs of any garage which, subsequently, supplied and fitted one of their non-road legal bulbs, only to be sued later by a disgruntled motorist, possibly for inciting them to commit the offence of driving an unroadworthy vehicle at the very least. Tellingly, not one company would answer this question.

Therefore, while there are a number of upgrade opportunities available, we recommend that you do not entertain fitting non road legal bulbs. We shall leave the final say on the topic to the Retail Motor Industry Federation (RMIF):

“As the representative body for the independent garage sector, we always advise members to exercise caution when being asked by customers to fit parts that the garage has not sourced for itself, or when being asked by customers to supply and fit parts that they may consider do not meet the requirements of UK legislation. It may be difficult to clarify if a part does, or does not, meet UK legislative requirements and even more difficult for a garage to verify the purpose for which the part is to be used; be that for show/off-road purposes, or on public roads, as the customer may not be fully transparent as to their intentions. The IGA has a clear message and advises its member garages not to fit customer-supplied parts”.

LED conversion bulbs, like this one, are not permitted to be fitted to an exterior lamp.


• Wait for bulbs to cool
• Always replace bulbs in pairs
• Check the condition of the holder and wiring
• Offer and explain upgrade choices, including emphasising the importance of realigning the dipped beams especially after a bulb change
• Hold the bulb by its base when installing it. Grease from your fingers can evaporate off the glass envelope and coat the reflector.


A problem with genuine LED lamps is that they are sealed units. Failure of the LED modules mean that the entire lamp unit should be replaced. Valeo told AT that, because car makers have rights on certain drawings and models, a very limited number of suppliers are permitted to produce them, meaning that aftermarket options are restricted severely. Yet, for Valeo headlights, you can still make savings by approaching a Valeo lighting distributor instead of a main dealership. Dependent on the communication system, an OE LED headlight will require beam setting adjustment and, most probably, ADAS calibration as well. We plan to cover more detailed OEM replacement headlight procedures, shortly.



About Autotechnician
Autotechnician is a magazine published nine times a year, delivering essential information to independent garage owners and technicians in the UK. Delivered both digitally and in print, autotechnician provides readers with technical, training, business advice, product and news, allowing our readers to keep up to date with information they need to run and work within a modern workshop.
Aftermarket Media Solutions Ltd, The Joiners Shop, Historic Dockyard Chatham, Kent ME4 4TZ
T: 01634 816 165
Company no. 09625886
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram