Has LED lighting efficiency reached a limit?

[polygonum_on_google]

The extra side illumination is on my LED car! It appears to switch on extra LEDs.

Drive in nice quiet areas and you hardly ever have to dip your headlamps. :-)

[Andy Burns]

Your car hasn't had the option enabled to light up the single fog lamp coresponding to the direction the steering wheel is being turned? I know some LED cars have a 'matrix' where it can control quite precisely where the lights shine (such as not in the eyes of oncoming drivers).

[polygonum_on_google]

Not that I'd noticed! There again, in three and a half years, I think I have only used the fog lights once or twice.

[polygonum_on_google]

Both the cars I have mentioned have their original headlamps (and eveything else).

[Max Demian]

My dad's 1939 Austin Cambridge had a solenoid that moved the reflector of the nearside headlamp when the (floor) dip switch was pressed; the offside headlamp was extinguished (which was made illegal later when they insisted that all cars have two headlamps working).

In the 70s the first cars to have halogen headlamps were rally cars with quartz iodine bulbs; they were all disqualified as they didn't dip and the cars had to be street legal even though they would never meet anyone coming the other way (hopefully).

[Andy Burns]

On UK models I don't think it's enabled from the factory (maybe it's not even legal here?) but can be enabled with ODB, provided the car has a steering angle sensor, personally I don't like it, seems to make people lazier about indicating as they thing the foglight is a good enough instead.

[Dave Plowman (News)]

Totally depends on the design. Early factory fit HID had separate main beams. And modern cars with this 'flag' need a second set of lights for the headlamp flasher.

[Dave Plowman (News)]

With projector lights - the type with the bulls eye in front of the bulb, the cut off is achieved with a french flag. And easy to make them so it can be set for LHD or RHD. This type of lamp usually has a spike of light to the nearside to see the edge of the road further, while still cutting it off from oncoming cars.

Other lamp types may do it all with the reflector, or a combination of reflector and fresnel lens in the lamp glass - although fashion has dictated most modern cars have a clear glass on the lamp.

[Dave Plowman (News)]

Quite. So all you are comparing is what was fitted - not the technology.

[Dave Plowman (News)]

Rally cars of the 70s had a whole battery of additional lights. Can't see what would be difficult in still having a legal dipped beam.

The first halogen bulbs were single filament. Hence many cars of the time having four headlights (and that before halogen). But twin filament halogen soon arrived.

[polygonum_on_google]

Never heard of the idea. Which strikes me as bonkers. Why on earth would anyone want to do that?

[Andy Burns]

You'll notice it now, specifically every Skoda peeling-off from the roundabout where you could have got out, if you knew it would be doing so :-)

[NY]

Turning on additional lights for *illumination* around a corner is an excellent idea.

But if it is done to make it clearer to other traffic which way a car is turning, as a supplement to the indicators, then it is a tacit admission that the indicators are not easy enough to see - which is no great surprise because modern car design puts the indicator lights very close to the dipped headlights or DRLs at the front and the brake lights at the rear. Whatever happened to *sensible* Construction and Use regulations which dictate placement so indicators can be seen even when there are bright headlights, brake lights or fog lights lit? Putting the front indicators within or under the front bumper, well away from the headlights, was a damn good idea - eg Hillman Avenger.

[Andy Burns]

Then you'd expect it to only come on if it was dark enough that the side lights or dipped headlights were on?

[NY]

Ah, is that not the case? That strengthens what I was saying that it's used partly to supplement the indicators, as an admission that indicator lights are no longer visible enough due to changes in where cars are allowed to have their indicators.

I'll have to look out for cars that turn on their front foglight as a supplementary indicator. I've seen some cars whose the DRL is turned *off* while the indictor light is flashing, to make it a bit more visible, but I'm not sure how that changes between daytime when the side/headlights are not on and night-time when they are turned on.

[polygonum_on_google]

On quite a lot of cars the DRL go off on the side that the indicator is operating. When driving my car it is very, very obvious. Road signs flash amber due to reflection of the indicator!

[Andy Burns]

yes.

This car must have the brightest indicators of any I've had before, in particular they are noticeable on retroreflective signs.

[Tim Streater]

So is the allegation then that just the one fog-light may come on when cornering. Very bad if so, will just cause confusion - just like all these tossers with only one headlight and the other pointing to the sky.

And it won't be winking so why should I consider it a supplement to anything? And it's the wrong colour. A completely bogus concept.

[Andy Burns]

Yes, surprised you've not seen any cars doing it, the feature is called "cornering light", mainly seems to afflict VW/Skoda, seems that when enabled it operates with either the indicator stalk, or the steering wheel.

[NY]

Interesting that such a recent car has a rev counter calibrated as 10,20,

30, .. x 100 rpm, rather than the much more common 1, 2, 3 x 1000 rpm which adheres to standard powers-of-1000 engineering notation for very large or very small numbers.

I'm trying to remember the most most recent car that I've owned that still had the old-style x100 rpm rev counter. Maybe it was my 1993 Golf Mk 3; I'm sure my 1997 Peugot 306 had x1000 calibration.