2014 low beam Halogen to HID retrofit worked out great

Hi all,

TLR; a 35-Watt HID retrofit improves brightness and has a very similar beam pattern to stock.

About a year ago, I bought a used 2014 Prius Plug-in and always felt that the low beams were extremely dim (actually, dangerously so). I was second-guessing myself and double checking that my low beams were on every single time I drove at night. I even restored my lenses (twice) until they became impossibly crystal clear, but this effort had no noticeable improvement. I tried a couple different brands of Halogen bulbs, but still I wasn't satisfied.

My main concern going retrofit was not the legality of it--Yes, I know H11 HID lamps in a housing designed for H11 Halogen are not SAE approved and therefore not road legal. Instead, my considerations for myself and others were 1) retain a warm-ish white color temperature, 2) maintain a controlled beam and similar glare for oncoming drivers, 3) avoid the "ground shadow" caused by the return electrode 4) don't go overboard with the extra brightness. I'm happy to report that my little $40 gamble paid off. I'm super stoked with the results.


For comparison, here is the beam pattern for H11 halogen bulbs. I had 1 month old Philips Halogen H11 X-tremeVision ("up to 100% More Vision") installed before the retrofit:


Here is the beam pattern for the 4300K 35-Watt HID kit off of amazon:


As you can see, both patterns are very similar. The small, partially-illuminated area on top of the cutoff is not as uniform with the HIDs, but they are more than acceptable in my opinion (I've seen more glare and random streaks from other OEM headlights to be honest). Not so clear in the comparison is that the lower left and right corners have a touch more light which helps immensely with cornering visibility (speaking of which, I wish the Prius had cornering lights). This was one of my main gripes with all of the H11 Halogen bulbs I tried. Also, there's no ground shadow from the return electrode (win!). I was surprised how similar the beam pattern looked with the retrofit--even the leveling was retained.



This last picture shows a comparison of the HID's 4300K color temperature compared to Halogen. The driver's side low beam has the HID installed. It's just a tiny bit whiter, still warm and not blue at all which is what I wanted. While not obvious in pictures, I'd say the HID lamps are about 1.5x to 2x brighter. 35-Watt HIDs is definitely enough for me (they have a 55-watt kit which I passed on).

Some departing notes: the HIDs take about 30 seconds to fully warm up to their warm white color. The initial 10 seconds starting from cold are super blue and dim. I don't know the reliability of these bulbs and ballasts, so I plan to carry my used halogen bulbs in the glove compartment in case one of them goes out.

 

This is the first time hearing about squirrel finders. That's cool!

I'm thinking the glare without modding the SFs is acceptable. But just to make sure, I want to measure the brightest area above the cutoff (somehow. I don't have a real light meter) and compare it with a much brighter headlight setup like in our Tesla Model 3. My subjective feeling is that the Prius is still dimmer than other cars since road signs feel like they're blinding me in the Model 3.