LED headlamps are in their early childhood. Will they become the popular kid seen everywhere and emulated by everyone? Or will they be that strange kid who's really smart but doesn't have many friends? It's up to us. We are more or less all aware of the various cost, price, and marketing reasons why Xenon headlamps have utterly failed to even slightly approach the volumes predicted when they first hit the streets in the mid-1990s. They were going to banish the halogen headlamp from the developed world's highways and roads, remember? Instead, they scarcely made a dent and the halogen bulb is still overwhelmingly the most common headlamp light source. The decisions that must be made right are greater in number and complexity with LEDs than with Xenon or halogen technology, so perhaps this is a wise time to take a look in the rearview mirror and ponder some of the things we didn't do as well as we could have in the past, so we don't make similar errors again.
Consider the HB2 ("9003") headlight bulb, introduced as an acceptable headlamp bulb in the North American Federal regulations in 1991 and known only thereunto. It looks, fits, connects, and functions the same as the H4 headlight bulb introduced in the international European regulations two decades earlier in 1971.
