HID Add-On

Not to mention that the OEM HID has a shutter to partially mask the beam for 'low-beam', versus fully open for high-beam.

 

My only experience with HID is the Chrysler Pacifica a friend has. I honestly didn't care for the low-beam output, the HID low beam has a VERY low and sharp cutoff.

I also didn't care for my Prius headlights at first. They were misaimed from the factory so high that even truckers were flashing at me. Proper headlight aim with a digital aiming machine has given me the best headlights I've ever used.

As far as converting to HID, I thought you also needed headlight washers? I read somewhere that any grime or salt residue on the headlight creates dramatically increased glare for oncoming drivers.

Proper aim is absolutely critical. You can't just guess and need the proper digital aiming machine. The one my local Autopac-certified shop used was made in Belgium, and has a laser to verify the windshield centerline, headlight centerline, and bumper centerline. Here in Manitoba, Autopac (Provincially owned car insurance) requires headlight aiming after collision repair.

Oh, remember that most HID conversions are for low beam only. HIgh beam is still halogen. I spent some time today at Mercedes, Audi, and Lexus dealerships, and all their cars and SUV's with HID are for low beam only.

 

I wish that during our annual inspection (or smog check) here in the US, the technician would examine the beam level & glare amount with some equipment & require the owner to adjust the projection until it gets a pass. And this applies to all headlights; halogen and HID, OEM and aftermarket. I have been blinded too many times by DOT-approved, SAE-compliance & fully factory-installed HID headlights from the new Range Rover & countless other brands.

 

Pay a visit to www.hella.de and wade through their documents. They appear to require headlight washers on all their Xenon (HID) headlight assemblies. As an example, the retrofit kit for the VW Golf requires headlight washers.

http://www.hella.com/produktion/HellaCOM/W...L/Double_HL.jsp

Since the Xenon low beams can be so much brighter if improperly aimed, it should be mandatory that the proper digital aiming machine be used to set the initial aim. The automatic adjuster can be used to compensate for loads.

You should only have to aim your headlights once in the car's life, unless it has been involved in a collision. Headlight aim shouldn't change unless you take an impact to the front end.

 

Tideland the stock HID has the electric level adjusters and the shutter adjuster, most after market ones are only the light globe and it fits in the stock headligh housing. Most of those kits come with the washer unit. Personally I went with Sylvanina Silver Stars and for the price and the amount of light and ease of installation are fine for my limited amount of night driving. Bough them at the Real Canadian Super Store, cheaper than Canadian Tire.

 

I think you fail to understand. The HID has additional components that a halogen doesn't have, which would make it difficult to impossible to retrofit to HID.

There is only one set of bulbs in the HID assembly. In order to differentiate between low and high beam, a shutter makes that change.
Also, HIDs require an auto leveler. The HID equipped Prius has a sensor under the rear of the car to detect car tilt in relation to the ground caused by car payload changes. This in turn sends a signal to a servo in the HID assembly to change the level of the beam so it is straight.

So, you couldn't just get an HID bulb/ballast. You would need a shutter, a leveler, and a level sensor. I would imagine adjusting for the proper lighting pattern would also be a problem, even if you were to solve the other ones. If you use HID only for highbeams (if high and low can be separated), then you probably wouldn't have to worry about beam pattern or level.

If you could get the OEM HID assembly, you would have a better shot at the conversion.

 

For halogens, its usually a separate bulb or separate filament.

 

The +2004 Prius uses an H4 style bulb, with different filaments for low and high beams. The filaments also operate at different wattage, typically 55W high and 45W low, or 55W high and 50W low.

If you carefully examine the H4 bulb, or for that matter any bulb from a single headlight system, you'll also notice the location of the filaments are different.

The low-beam filament typically shines upwards, which is reflected by the top of the housing through the lens (Clear or fluted) and down to the road. You'll notice the Prius also has a shield, or shutter, to more precisely aim the low and high beam filaments.

I see nothing wrong with the halogen headlights in my Prius. Once they were properly aimed, they are hands down the best headlights for night driving I have ever driven with. I wouldn't even bother with headlight upgrades. It would be cheaper and much more cost-effective to put on a bullbar with HID driving lights, like the expensive Hella Rallye 4000 HID.

The technician at the body shop also commented on how well designed the optics were on the Prius. It really impressed him, he even recalled the beam pattern image on his computer to show me just how sharp and well defined the pattern is. He claims most American-brand vehicles have quite poor headlights, but the Prius is top quality for lighting.

I've never had a new vehicle with properly aimed headlights. Some, like the four headlight system in my 1992 Honda Prelude SR, were only slightly misaimed. My Prius was the worst as far as being misaimed.

My 2000 GMC Sierra was aimed cross-eyed, with the driver headlight too low and the passenger headlight too high. Given how rushed assembly production is, I doubt anybody spends the time to properly aim headlights.