We got our Prius finally last Wednesday and I've been loving the LED headlight on our dark and dry evenings on the country lanes. Tonight however the skies opened up and it is raining cats and dogs and the headlights don't seem to work. Has anyone else noticed this in the rain? It is like the headlights are too white to be seen in the rain. I noticed a similar thing with after market HIDs on my other car when I had 6000K, whilst they were bright/white there seemed to be less light on the road until I changed to 4300K bulbs. I felt really let down by that expensive option of LED Headlight in the rain, I felt myself constantly switching to a full beam whenever I had the chance and no oncoming traffic. Never had that issue before with OEM Hids, but granted never had LEDs before.
I'm very happy with the LEDs om my Prius. My last half a dozen cars had HIDs, and the LEDs are very comparable in terms of brightness and color temp. FYI--6000K HIDs are much bluer than 4300K--and the higher the Kelvin rating, the less bright the light output, so it's not surprising you found the 4300K (which most OEM HIDS are) brighter.
I haven't noticed any marked difference, rain or dry. Then again, it doesn't rain here very much (sorry, I couldn't help it ).
This is one reason why I didn't bother with the LED option. I too have noticed the higher the color temperature, the less the perceived light in poor weather conditions. I am actually looking at installing PIAA Plasma Ion Crystal low beams for the winter months. I liked the way they worked in my fogs in the past through a winter storm.
I haven't noticed a large degree of difference during inclement weather. I have noticed that low beam illumination seems to be a great deal less than any vehicle I have owned previously. I thought they might be out of adjustment, but I checked and they were right where they should be according to all the measurements. I, like you, find myself resorting to high beams frequently to see far enough in front of the vehicle. I've seen this mentioned in other threads as well. I'm almost tempted to adjust them up higher than the specification, although I don't want to be blinding other drivers.
I have adjusted mine upward...without blinding on-coming traffic...makes a huge difference! From factory, it is aimed way too low.
LOL Yes I bet in SF Bay you don't get much rain... Bringing them up a little sounds interesting, so that is possible with automatic levelling that is standard with them? I don't have specialist equipment but a great huge sectional garage door. Is there a particular rule of thumb to follow in distance of the car and percentage to bring them up in order not to overdo it?
I've had HIDs on my cars for some time now. Since they are very bright, they have a sharp cut-off at the top of the beam, to avoid blinding oncoming traffic, unlike halogens which can project higher with less risk. Pix here: The LED headlights appear to have the same characteristics (pix here: http://priuschat.com/forums/gen-iii...fog-lamp-off-comparison-photo.html#post922457), so somebody who is new to HIDs or LEDs might think there's an issue, and want to raise the aim. I think it's a mistake, since you're risking the safety of oncoming traffic. How would you know if you did or not? They're aimed the way they are for a reason, and it's not to make them ineffective.
The auto adjust only compensates for added weight in the back, the headlights still need to be adjusted correctly. See post #15 in this thread if you wish to see how I did mine, it's quick and easy. http://priuschat.com/forums/gen-iii-2010-prius-main-forum/69497-shaded-lights-getting-me-down-2.html
