Exactly. In additional to the cost, bright LED still emits lights from a very concentrated area. Though, LED is relatively cooler than halogen or HID, the heat density is very high, which causes reliability concern.
Anyone have any idea how they accomplish this? Lower wattage? Does this translate to lower lumens output?
Lower wattage per lumen. The actual brightness may be lower too - I didn't check. Mostly this new type of halogen lamp uses an infrared reflective coating on the inside of the bulb to keep the internal temperature higher. Tom
Actually, EcoVision was not the one that caught my eye. As the Prius comes by its 12 v. power more economically than a conventional car does, I doubt that savings would come anywhere near the claimed four gallons. I was interested in the one that might help me see better: [FONT="]CrystalVision Ultra :laser: [/FONT]
Conventional hot lamps radiate heat away from the bulb. LEDs, on the other hand, are poor heat radiators, so most of the heat stays with the device and is concentrated into a tiny space (the high heat density mentioned above). Heat management is one of the big challenges when working with high brightness LEDs. Think of it as being like a furnace verses a small soldering iron. The furnace makes lots of heat, but sends it around the whole house, keeping temperatures at a comfortable level. The small soldering iron makes much less heat, but will easily burn you if you touch it. It's a matter of heat verses temperature. Tom
On a similar note, does the Prius 12V supply seem "cleaner" than the typical car? I've had light bulbs last over 100k miles with regular use in this car that usually expired after 40-50k in previous cars (tail lamps, fog lamps, etc.). Any correlation?
I would guess this is the result of steady voltage, not cleaner voltage. Most cars use a simple voltage regulator that allows a bit more swing in voltage levels. Higher voltage will reduce the life a normal light bulb. Tom
I believe that's what I was thinking. A more steady voltage source w/ fewer voltage spikes (DC noise?).
Watch out for the LED stop lights in all 2004 and newer prius models. One of mine went very dim. I checked it and the LED is a special one of a kind prius only rube goldberg configuration that is not a replaceable bulb. I had to get the entire real light assembly replaced at a ciost of $350. This was nor a warenty 100K items like the hybrid system so I had to pay. The turn signal backup and running lights are all simple dumb replaceable bulbs. The brake light is this only odd LED system. It's the dumb award winner for Toyota. What were they thinking !! they weren't.
just because you had failure of the system, does not mean that everyone does. In fact, most new Toyota's now in Europe have had LED's at back, and I have to yet to see single failure. On the other hand, due to DRL requirements of late, failures of "simple" bulbs and HID's are embarrassing. Unlike in USA, full light is emitted by European DRL's, and hence life of bulb (even expensive long life ones which are given under warranty) is significantly shorter than before. Toyota expects 15 year life of LED headlights in new Prius. LED lighting is the future, it is becoming standard accross many industries including auto.
