2023 Prius (prime SE) headlight aimed low. Adjust?

It's not supposed to go all the way into the horizon. If you're driving on a dark country road and need more light being down the road use high beams/auto high beams.

 

I'm in agreement that the headlights are too low. I will be adjusting them later this week. Page 542 of the manual explains how to make the vertical adjustment.

 

duplicate post

 

Why don't you guys take it back to the dealership to get it properly aligned - rather than blind on-coming traffic??? It's under warranty? You can't down-beam the low beams, especially running those 6000K LED white lamp bulbs.

Just my two cents and don't be surprised - if on-coming traffic is constantly high-beaming you.

 

My 2021 headlights were fine but not the 2017...they were up so high oncoming traffic constantly flashed their highs at me...telling me my brights were on....very annoying.

Dealership will adjust them for free with new vehicles.

 

According to standards, the left-hand-side cutoff should be 0.4 degrees (0.7%) down for the US, and 0.57 degrees (1%) down for UNECE.

So that should be illuminating the left-hand side of the road for about 90m/300ft in the US or 63m/200ft elsewhere. 100ft is too short. (The angles are fixed, independent of the height of the headlights - so the higher they're mounted, the further you get to see.)

Searching now I see a lot of crappy "guides" basically telling you to set it horizontal, which might explain why people are getting dazzled...

The AHS system in non-US cars does have a function to raise that dipped beam angle at higher speeds and based on traffic visible ahead. (Meaning it switches from "class C" (standard passing beam) to "class E" (high-speed/motorway passing beam) in UNECE standard jargon.)

 

If someone cares to measure from the ground to centre of their headlight, I could lay it out in autocad.

 

Yeah, while searching I found papers calling for changes to the standards to address that - increasing minimums in various areas - such as this one, but I'm not sure how many of those have been incorporated. LED projectors have far less natural spill, meaning a "conformant"-but-undesirably-tightly-lit pattern can easily arise.

Similarly I'm a bit sceptical about the LED reversing lights here - I'm sure they're fine for signalling, but they're really not directing much at the actual ground so I can actually see... (And the standards don't technically require them to - lots of ground light is permitted, but not required).

In the other direction, one of the things that's surprised me is how incredibly bright the front indicators are. All the road signs flashing orange at me! It seems that's a legal requirement - if your front indicators are less than 2cm away from the headlamps they have to be "class 1b", which means as bright as DRLs, so brighter than any other lamp. 10 LEDs used per indicator in the Prius, apparently.

The cheaper spec cars look like they have their indicators 4cm away, so they can be the basic brightness - one LED module.

 

A photometric measurement of a Gen 5 had the headlights at 63cm, which is where I got the above figures from. Not going outdoors in the dark and cold to get that more precise, sorry! I doubt there's a huge amount of variation between generations, and I further doubt it will ever be that precisely aimed.

 

Double post. Finally got me. @Danny, please fix this damn mess of a website.

 

One thing that bugs me is when someone across the intersection "may" be signaling a turn, but their headlights are on, and their indicator lights are so close to the headlights, it's nigh impossible to discern if they're flashing. I think the current rules as to how close they can be are too lenient; it's dangerous.

 

630/254=28.4 (inches), say 28.5".

 

Something's not quite right there. I'm working in metric, but I get 90.2m = 296ft. (0.63 / tan(0.4°), or 0.63 / 0.007)

 

For aiming, you can just scale the distances down. Using the 0.7% rule - when you move the car X away from the wall, the edge should drop by 0.007X. That seems to come out quite neatly to 1 inch for every 12 feet. Over here in metric land, it's 1 cm for every metre.

It's not supposed to be black above the sharp cut-off line - there are a bunch of minimum light requirements for upwards and outwards light too, several degrees above horizontal and to either side, so you can see signs.

However, I suspect for a halogen reflector designers would have been working to stay below the maximum above the cutoff - struggling to control beam scatter.

Whereas for a LED projector, especially with a physical cutoff shutter like the non-AHS Prius headlights, designers probably find themselves working to get above the minimum there.

A constant incline is still flat from the point of view of aiming. It's cresting hills where it goes to pot.

 

I get annoyed at these vehicles with the "auto" headlights that come on when it dark. Great idea BUT the stupid cars don't turn on the rear lights....so I'm always seeing drivers with zero lights on in the back yet their headlights are one. Do you WANT to get rear-ended????

Thank Goodness Toyota's don't do this nonsense.

 

They're probably just driving with their DRL. Drunks do that a lot, since their pupils are already dilated. On older cars, no dash lamps - no headlamps. These new dashboards always has a back-lamp on. You'll be surprised how many people don't realize what that little light bulb symbol in your dash board means....

 

I concur, initial brain-fart when converting 630 mm dimension to feet and inches.


metric:

Slight variations cus I slightly rounded the imperial headlight to ground dim.