Many people imagine that fuel efficiency stops and starts with engine technology and driving technique, but there's a little more to it than that.

Making a fuel-efficient vehicle involves a holistic approach that examines every aspect of a car's design and tries to reduce its impact on fuel use--and even the humble headlight can play a part.

Audi's range of LED headlights is just such a technology, and the European Commission has certified it as an official fuel-saving technology.

In tests comparing non-LED and LED-headlamped Audis, those with the new technology were measurably more efficient--with CO2 reductions of over 1.6 grams per mile.

It's due to the relative power consumption between LED headlights and more traditional halogen units.

While the former consume only 80 watts of power in a low beam setting, the latter can draw up to 135 watts. That power needs to come from somewhere, and that somewhere is extra load on your car's engine as it spins the alternator.

By reducing this load the engine doesn't need to work as hard--even if it sounds like a tiny amount in comparison to the engine's overall workload--and uses less fuel as a result.

Audi's use of LED technology stretches back to 2004, when LED daytime running lights debuted on the Audi A8 W12 luxury sedan. The R8 supercar was first to use fully-LED headlights in 2008, and since then the tech has appeared on the A6, A7 Sportback and A3 as well.

Different Audis use different types of LED headlight units. The compact A3 features 19 LEDs for each unit, supplemented by modules for all-weather and cornering lights, whereas the luxury A8 uses 76 LEDs per unit--for precise control of beam patterns.

Not only is fuel efficiency increased, but safety too--a color temperature of 5,500 Kelvin provides light similar to daylight, much easier on the eyes during night driving--and of course a better view, too.

Other manufacturers also offer LED technology in their headlights for certain models, including Toyota, BMW and Nissan. And until laser technology becomes commonplace, they're the best choice for both efficiency and brightness.


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