Z4-forum.com

About three years ago I upgraded my Santa Fe head lamp bulbs to Philips H4 high Intensity bulbs because the factory ones are a bit dull. This morning they both blew as I started out on my rainy 6.00am journey! (so I swapped to my Z4).

Can I assume if one bulb goes it overloads the other? And that the brighter lamps burn brighter but at a cost of lifespan? I kept the original bulbs and put them back in after checking fuses etc. They still work fine.

What are others experiences of these brighter bulbs?

No, one blowing won't overload the other - they both have their own 12V feeds so are not connected together.

Bulb brightness and lifetime are very much related though. This page gives you a good idea of lifetime vs performance etc...

https://www.philips.co.uk/c-m-au/car-li ... bs/halogen

I use Osram Night breakers and when one goes the other is not far behind - higher intensity lights burn out faster, but its worth the trade off to me as they are a huge improvement over the standard candles.

Wow, thanks for the link, cant believe my bulbs only had a 400 hour lifespan. That is just 4 hours a day for less than a year.