W5W bulbs fall under Group 2. What does that mean to you? According to UN Regulations 37, you can use these bulbs for any application, except in headlights. You’ll commonly find them in the interior lights as well as sidelights. If you choose, you can use these bulbs for your number plates as well.
Most W5W lamps utilize halogen. Nevertheless, you can find LED bulbs as well. Halogen lamps last for about 1, 000 hours and produce low quality light, and this one is not exempted from this general rule. If you want to use your W5Ws on the exterior of your vehicle, you may need to upgrade them to LED to be able to get a longer-lasting and brighter light. But you can also upgrade if you are using the lamps for your interior. Remember, there’s no better way to achieve a cooler and more modern look than doing this.
W5Ws are dual filament bulbs and use W2.1×9.5d base. They consume 6 volts and produce 5 watts. The wedge-base lamps are dual beam bulbs as each of them has a single filament. You will find many people use them in reflector lights. As you can see, if you upgrade your halogen W5W to LED, you can use it for absolutely any function other than headlamps and get the best quality light for a more extended period.

Consultant in the area of automotive lighting solutions. Previously working as a lighting sales manager for various light bulb brands, collected intensive expertise for effective vehicle lighting & signaling systems that are compliant with the UN regulatory requirements and standards in the United States and Canada.