Headlight Globes - Tech Talk
— June 06, 2021 | 2 min read
Like household globes, headlight globes come in many different shapes, sizes and fitments. How easy would globe replacement be if every vehicle used the same one? Unfortunately, automotive manufacturers have to choose a specific headlight globe and fitting to meet a long list of requirements and standards for each vehicle, so you’ll need to wait a little longer for the day you can walk into an auto parts store and ask for a “new headlight globe” without any follow up questions. Fortunately, our online application guide on the Narva website makes it easy to determine what globes are in your vehicle. We thought we’d share with you some background on classification of the humble halogen globe, which is still the most common headlight configuration on the road.
All bases covered
Choosing the correct base is something most of us don’t have to worry about. Most modern headlight globes have the base (also known as the cap) built in, allowing you to simply change the globe when it expires.
For the most part, H1, H3, H4, H7, H11, HB3, and HB4 classifications are the common base selections shared between vehicle headlights and accessory lamps. However, some more recent and manufacturer-specific classifications now exist, such a H15, which can be found in several European vehicles. If you’re unsure which type your car has, you can consult your owner’s manual, or remove the globe and check the stamping/ink on its metal base. This will also help you achieve a direct fit replacement when upgrading halogen globes to aftermarket LEDs, such as Narva Surefit globes.
Bulb classifications
Those base classifications we spoke of? They also refer to the globe part itself, as the electrical connector and ultimately globe type must fit the same pattern as the socket they attach to.
H-type globes, for example, fall under the Group 1 classification. This standard is determined by the United Nations who have set an international standard (UN Regulation 37) for classifying vehicular globes, ensuring consistency across different countries. Importantly, these classifications also govern the approval process used by national testing bodies and their subsequent gradings, including ECE (Economic Commission for Europe) and ADR (Australian Design Rules).
The other groupings for various globes found throughout your vehicle are as follows:
Group 1 – lights used to illuminate the road (i.e.: headlight globes, driving light globes, fog lights).
Group 2 – signalling and marker lights (i.e.: cornering globes, reversing lights, numberplate lights).
Group 3 – older vehicle lights (i.e.: no longer standard fitment, manufactured as replacement only).
Filament types
Halogen headlight globes use a conducting wire or thread with a high melting point known as a filament, which is heated by electrical current to produce light. The filament appears as a fine wire supported by two rigid wires – often made of tungsten and coiled to produce more light.
In some instances, you may notice more than one filament within a globe. This is usually when a single globe serves multiple functions, such as switching between low and high-beam headlight operation (e.g. H4 globes), or in the case of incandescent globes, swapping between park light and brake light functions (e.g. P21/5W). The other H series globes we listed previously (H1, H3, H7, H11, HB3 and HB4) are all single filament globes.
Nominal power
Broadly speaking, the different globe fitments listed above can produce similar volumes of light, but the voltage they require to operate (in most instances 12V or 24V), the wattage they produce (also known as nominal power) and their lifespan can differ from globe to globe. It is important to be aware of recommended voltage and power when replacing them, so that you get like for like.
As an example, 55W is a common power output found in low-beam halogen headlight globes. You may be able to obtain the same fitment in a 100W version, thinking the latter will give you more light – and you would be right – however, using such a globe where it is not specified could also damage your vehicle’s electrical system, as well as headlight plastic/lens if it produces too much heat, so we don’t recommend it. Consider instead replacing your halogen globes with Narva performance globes, which are direct replacements that give you more light output without drawing any extra power and are ADR approved, so you won’t be breaking any rules.
If you’re ever unsure of which globe is correct for your vehicle’s application, as well as upgrade options, you can always check the Narva Globe Application Guide.