Sealed Beam—When All U.S. Auto Headlights Were Identical


There is quite a bit to be said for that. With headlights now integrated into car body styling they are effectively unique for a given model and few year period.

They are now massively more susceptible to damage and expensive to replace.

Another area where standardization would help is batteries for hybrid cars. Due to the relatively small capacity needed for a hybrid, packaging efficiency is less important than with a full EV. But, as you also have the costs of the internal combustion hardware, limiting replacement costs for the hybrid battery is advantageous.


Expensive doesn’t even begin to cover it in my opinion. In my early 20s, I worked at a collision repair shop while going through community college courses. This was in the early 2000s. Back then, a headlight assembly for a run of the mill Toyota or Honda was roughly $400. A couple of years ago, for my 2006 Volvo sedan, the headlight assembly was close to $700. This is just the assembly folks, not talking labor to put it in.


On 2022-07-26 we had a post here, “Inside a Tesla Model X Headlight”, in which Big Clive tears down a Tesla headlight assembly with “no customer-serviceable parts inside” that was sent to him by a viewer who reported the replacement he had to buy cost £1200.


Yup, that’s the stuff I am talking about. And generally speaking the assembly could be fixed with a rather inexpensive component if it was only sold individually. But, like with many things these days, fixing stuff yourself voids the warranty and precludes Auto manufacturers from robbing you blind in component costs. Have any of you been following the cases of farmers suing tractor manufacturers because of the warranty stipulations forbidding farmers from working on their own machines? In the past farmers were able to do this as a means of keeping costs down since they operate on such slim margins. Now, with repair costs so high, farmers are put between a rock and a hard place.


Correct, pre chip tractors sell at a premium because of John Deere and other manufacturers Microsoft level greed!


May be less warranty stipulations than simple hardware/software security measures.

The “right to repair” movement largely involves requirements for the manufacturers to provide third party repairers the ability to do the same software work that authorized repairers do.


That’s the detail I was missing. Thanks CT. Yes, the issue is that third party repairers can’t access the software needed to perform the repairs thus causing farmers to take out yet another loan for a multi-million dollar tractor (have some of you ever looked up what it costs to purchase a combine for instance?) and driving them further into debt. The corporate world has become ever bit as evil as the communists were/are. I suppose that is why there is a black horseman carrying scales (weights and measures), corporatism is an apocolyptic killer.


They are TOO bright (new ones)


I’ve always wondered why they don’t put polarisers on headlights with a specified orientation and polarisers in windshields with a rotated orientation so that the oncoming headlights would be dimmed and not blind drivers in the other lane. If you chose the polarisations correctly, the windshield polarisation would also reduce glare from snow, ice, and standing water on roads.

Well, it turns out that Edwin Land, the Polaroid guy, thought of this back in 1932 and received U.S. Patent 2,031,045 on 1936-02-18 for “Means for avoiding glare from automobile headlights” (full text [PDF]).

The invention has for its object generally an improved construction and arrangement of parts for avoiding glare from headlights and similar sources of light in an efficient and economical manner.

More particularly, an object of the invention is to provide a source of illumination which gives light of a character from which the glaring characteristics may be readily controlled and substantially cut ofi by means arranged to cooperate therewith and which still admits of adequate vision.

A further object of the invention is to provide means for diminishing or eliminating the glare from sources of illumination by interposing between the said source and the person viewing said source a plurality of polarizing bodies each comprising a set or hardened transparent suspending medium in which are embedded colloidal polarizing particles with their axes of polarization substantially aligned.

Why didn’t this happen? My guess is that at the time, with headlights relatively dim, the loss of intensity due to polarising their light and the absorption by a polariser in the windshield of vehicles were judged to pose a greater risk in night driving than any gain from reducing glare. Also, there would only be a benefit if both vehicles were equipped with polarisers, and with the new car market nearly moribund during the Depression, it would take many years before a substantial fraction of cars on the road were so equipped.

Today, in Safetyland, regulation has imposed such a degree of sclerosis that nothing will ever change again, except to make things worse and harder to use.


I’m curious why the French yellow headlights died out. I’m my experience they were very effective for driving visibility and easy on the eyes for oncoming drivers.


Selective yellow headlamps, standard in France for all vehicles until 1993, were banned by the European Union ECE Regulation 48 on 2016-10-08.

Just think of it as another of the multitudinous stupid ideas spouting from Brussels.

Yellow headlights are particularly effective in piercing fog, which is common in Europe in fall and winter months. They not only improve visibility for drivers of vehicles, but make their vehicles visible at a greater distance to oncoming vehicles and pedestrians on the road.