alpine-al

Regarding the LED headlights not offering any better lighting at night, it is most likely due to US regulations that limit the light output. According to an article in the Sept 2014 issue of Car and Driver, the US limits headlights to no greater than 150,00 candelas (cd). In Europe the limit is 430,000 cd.

Typical luminous intensity of high beams:

--> Halogen 162,500 cd (energy drawn: 220 Watts per pair)
--> Xenon .. 175,000 cd (energy drawn: 140 Watts per pair)
--> LED ..... 237,500 cd (energy drawn : 72 Watts per pair)
--> Laser ... 425,000 cd (energy drawn : 25 Watts per pair)

In the US, the high beams are downgraded to get below the 150,000 cd limit.

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9972RS

^ is this a software issue, i.e., reprogram for euro LED? If so, then the LED upgrade is worth it.

Jimmy-D

^ That would be interesting. I am sure some one can manipulate that feature. But, while I was showing my Wife the LEDs( she was actually pretending to care); She did comment that she thinks they are very bright. If we were to have this updated to the Euro spec; would it drive other Drivers nuts with the brightness? Would it be too much?? You are asking to more than double it's output.

9972RS

why? the brighter the roads the safer it is for everyone. As long as it's not shining directly eye-level

Jimmy-D

^True but will it be a distraction as the car jumps around on uneven pavement. I just could not imagine twice the brightness. There must be a reason why the US has such strict regulations- or may no reason at all

Mike in CA

Based on those numbers LED's seem a bit of a waste. The Xenon's are limited as well although the color temperature and precise cut off that can be achieved are advantages as they would also be for the LED's.... for $3K+ more.

silverrules

Jimmy, you nailed it. Enjoyed reading it.
While we are on this topic, when in Auto mode why the gears shift to 6, or 7th gear at such low RPM? You would never do this in a manual car.

neanicu

Silverrules,it does the same thing in regular PDKs found on Carreras. To me it's annoying,but it's programmed to get to the tallest gear ASAP for fuel consumption reasons.

brass4321

I may need to remove from my build. No automatic high beam, limited output, I could add sport chrono and more for that.

Jimmy-D

^^^I have to confess; I have yet to even drive this car in Auto. I did once entering the garage - I am not kidding

silverrules

You are not missing much Jimmy.

squid42

The BMW folks had the same discussion with the same data (some bimmer... some forum... sorry).

They put US F80 M3 cars with and without LEDs on the same garage door.

There was no question that within the lighted area the LEDs were brighter. People did not measure further, that leaves three possibilities:

• BMW exceeds US specs on the LEDs (possibly to upsell them)
• BMW artificially cripples the Xeons in the US (definitely in an attempt to upsell the LEDs)
• It is more complicated. The total candellight power is one thing, but where is it going? At the same candle light, can you bundle more of it in the supposed-to-be-illuminated area? How much stray light is there with the Xeons that goes elsewhere and is useless?

I never read that US spec. Is that a limit on brightness inside the illuminated area or a limit on total light output?

What about limits on light that is involuntarily ending up outside the specified area? Surely that much be regulated.