Today many cars offer cornering lights. But not all of them deserve that name. There are several types which differ significantly in performance.
Let’s start with the best cornering lights that money can buy. They’re the dynamic ones where the light doesn’t just follow the movement of the steering wheel. In geo data-based systems, the headlight points slightly into the bend before the driver has even started to turn the steering wheel. The car knows from the digital map (“geo data”) that a bend is approaching and takes into account the layout of the road. Those features are still extremely rare though and can only be found in very expensive cars.
The standard common dynamic cornering lights are already available in compact classes and are entirely sufficient for most drivers and their driving profiles. The headlights are electronically connected to the steering. If the driver turns the wheel, the light follows in the same direction up to 15 degrees. That’s suitable for most curve radiuses on country roads, and certainly on highways. Larger swivel angles are therefore not permitted. Dynamic cornering light is mainly created by a lens module slightly swiveling in the headlight. Lenses – referred to as projection systems by experts – are not necessarily required though. There are also systems in which reflectors are moved small distances.
Dynamic cornering light offers an optimum range at all emission angles because it comes out of the main headlight; and it operates at all speeds. The only time when the headlights can’t move is when the car is stationary; it must be moving. And because nobody needs to illuminate a bend during the day, many car manufacturers automatically switch off the cornering light function via a brightness sensor.
Static turning lights are in a completely different league. They’re the headlights that accompany every bend and turning maneuver in city traffic, and then dim down, going out eventually. Many people like the dimming in particular. They see it as a fancy design feature. Otherwise, opinions on static turning lights vary greatly. Better visibility is provided essentially only by the rather rare ones where the headlight used is more or less on the same level as the main headlight. Usually, however, manufacturers use the lights that also serve as fog lights. Not only do they sit very deep, but they also have a light distribution which is not exactly designed for a long range. For this reason alone, the static turning lights can only come on at speeds of up to 40 kilometers an hour. The whole thing is controlled automatically and, as with dynamic cornering lights, via the steering angle sensor, which every car that is equipped with ESP has on board anyway.
It’s different in the US where turning lights have been around for decades. But there they simply come on with the indicators.
The question whether you want to have and pay for dynamic cornering lights very much depends on your driving habits. If you’re mainly driving on highways and in cities you won’t benefit that much. Country road traffic in North German lowlands isn’t exactly the terrain for dynamic cornering lights either. It’s a different matter if you’re often driving on twisty country roads or even serpentine roads. Static turning lights which are generally significantly cheaper fall under the “if you like” category. Often the trim takes that decision out of the buyer’s hands: in many cases they’re available as standard or come in a package in combination with the fog lights they’re used in.