Bulbs H4

H4 automotive light bulbs: type, uses, characteristics

Initially, the name H4 was used for double-filament halogen lamps. Nowadays, it is also used for xenon (HID) and LED versions, which are marketed by manufacturers as an alternative to standard ones.

Where are they installed?

H4 automotive light bulbs are installed in headlamps. They can produce both a high beam and low beam. They are not used in other lighting units, as switching light intensity and direction is particular to front headlights only.

Characteristics

The halogen versions of this type have two filaments, while a special screen to cut off the dipped beam is installed in the headlights. Before purchasing, make sure that LED H4 components are road legal in your country. These work on a similar principle, but have two diodes instead of filaments. Bi-xenon lights have a special moving element (a shutter or a base), that allows changing of light direction and intensity. Their installation in standard headlamps is not always permitted and requires specialist assessment.

They can have P43t, P43t-38, or P45t-41 bases. Their output is generally 100W/90W, 75W/70W, or 65W/55W, while the voltage is 12V and 24V.

Specialists from our online shop will help you choose the right products for your vehicle operating conditions. With our wide range and expert advice, you’re sure to be satisfied with your purchase.

How to choose H4 automotive bulbs

When selecting light bulbs, always check the car manufacturer’s recommendations and the specifications of the parts currently installed in your vehicle. Every lighting unit has its own designated type. Installing components that don’t match the factory-installed equipment specifications could result in damage to the headlight or a fine.