## EU validates Audi LED headlight technology as fuel saving

##### 11 April 2013

The EU Commission has measured the fuel savings achieved by LED headlights from Audi—testing the low-beam headlights, high-beam headlights and license plate light in dynamometer testing. In the ten NEDC cycles that the Audi A6 ran through, CO2 savings were found to be above one gram per km (1.61 g/mile).

As a result, the EU Commission has officially identified the LED headlights as an innovative technology for reducing CO2 emissions. Audi is the first car manufacturer to be certified for this technology.

Conventional halogen units consume more than 135 watts of power in their low-beam headlight mode. By comparison, LED headlights from Audi operate with significantly better energy efficiency—the low-beam lights only consume around 80 watts.

LED daytime running lights made their debut in the Audi A8 W12 back in 2004. Then, in 2008, the R8 sports car became the world’s first car to feature full-LED headlights. Today, this high-end lighting system is available in five model series: the R8, A8, A6, A7 Sportback and A3.

Audi designs the LED headlights very differently for different models. On the A8, for example, 76 light-emitting diodes are used per unit. On the Audi A3, 19 LEDs operate in each headlight to generate the low-beam and high-beam lights; they are supplemented by a module for the all-weather and cornering lights as well as a light guide for the daytime running lights, side lights and turn signals.

Besides improving energy efficiency, LED headlights also offer safety and comfort benefits. With a color temperature of around 5,500 Kelvin, their light resembles daylight and hardly causes any eye fatigue. The LEDs are maintenance-free and designed to last the life of the car.

Very near future mass produced 200+ lm/watt LEDs will more than double the efficiency of 80 lm/Watt current LEDs and reduce energy consumption below 40 Watts.

Mid term 300+ lm/watt LEDs will further reduce energy consumption.

LEDs can be timed to further reduce energy consumption.

Ultra high efficiency on-board heat pumps could reduce energy consumption even more for all HEVs-PHEVs and BEVs and increase e-range.

New cars are a good application for LEDs: low voltage DC power source, need for a beam rather than diffuse light and can incorporate good thermal control. There is also less compromise as no need to be compatible with old designs (ie bulbs) given that the light will last the lifetime of the vehicle. Should also be one of the first places to make financial sense as the cost of electric power is higher than in the home.

But there is just not that much fuel to be saved via more efficient lighting and so touting the 1 gCO2/km seems pedantic. Is the point that other manufacturers LED solutions are there for fashion but don't achieve the possible efficiency gains?

EVs have been very slow to adopt LED lightning (as part of the ongoing big oil conspiracy by GM, Toyota, and Fisker, well documented at various times here, by the demented).

Truth is, they are of insignificant worth for adding EV range - and obviously less useful for ICE vehicles, much less a V10, 525 bhp, $150k "car for the masses". BUT, they should definitely use them on EVs; the more green eyewash the better. Anyone who has ever built a low weight bicycle knows that you should never dismiss any weight saving out of hand, no matter how small. 5 grams on a shifter paddle, 12 grams on a rim, 4 grams on a sprocket, 0.5 grams on a spoke and so on. All these grams are unimportant on their own, but together add up to kilograms. Now apply this wisdom to building a high efficiency EV you'll see the same exercise in finding as much 50W-here-and-25W-there-savings to add up to something significant. TT, I expected you to have learned by now that small, incremental changes is what drives 99% of technological progress, not Hollywood style silver bullets or *magical* technological breakthroughs. Too many posters forget that incandescent light bulbs have a very low efficiency of 15 lm/Watt and LEDs have already reached 231 lm/Watt and will reach 300 lm/Watt (or 20X longer than incandescent) by 2015/2020. LEDs with 360 degrees beam angle exist. With their extra long life (30,000 to 100,000 hours) LED lights will not have to be changed for the duration of the vehicle. Vehicles LEDs will have a good trade-in value after 20+ years of use. Changing a single incandescent light in a car can cost xx$. That's why so many users drive with one+ incandescent head/rear light out.

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