Replacing old P21/5W halogen bulbs (the double-filament ones, often used for parking lights and daytime running lights) with 30W 2600LM LED versions is a very common upgrade. Beyond aesthetics, there are also some very specific technical and safety reasons.

Here are the main reasons to take the technological leap:

1. Visibility and Safety

LED lamps emit a much more intense and defined light.

High contrast: Cool white light (usually around 6000K) is much more visible during the day than the yellowish light of halogens.

Instant on: Unlike a filament that needs to heat up, an LED reaches full brightness in milliseconds. This is vital if the bulb also serves as a turn signal or brake light, allowing those ahead or behind you to react more quickly.

2. Energy Efficiency and Heat

Halogen bulbs waste about 90% of their energy as heat.

Lower consumption: An LED consumes a fraction of the watts of a halogen, reducing the load on the car's electrical system.

Plastic protection: The constant heat of halogens can, over time, bake the reflector or yellow the headlight's clear plastic. LEDs operate at much lower temperatures.

3. Longevity

While a P21/5W halogen bulb has an average lifespan of around 500-1000 hours, a quality LED bulb can last over 30,000 hours. In practice, once installed, you likely won't need to replace them for the entire life of your car.