What is the difference between position lights and daytime running lights?
4 Answers
Introduction to the difference between position lights and daytime running lights: 1. Position lights are generally turned on after dusk and are mainly used to indicate the width and height of the car while driving. Typically, position lights are white at the front and red at the rear. 2. Daytime running lights are designed to make the vehicle more visible during daytime driving. Their purpose is not to help the driver see the road, so these lights are not illumination lights but rather signal lights. Here is more information: 1. Position lights are located at the four corners of the vehicle, both front and rear, while daytime running lights are only at the front. 2. Position lights need to be manually turned on, whereas daytime running lights do not—they automatically turn on when the car starts and turn off when the engine is shut off. 3. Position lights are usually tungsten filament bulbs (halogen lights) with a yellowish and dimmer light, while daytime running lights are generally LED lights. 4. However, many cars now use the same light for both front position lights and daytime running lights, though the position light mode is dimmer than the daytime running light mode.
Let me explain this in detail. The width indicator lights, as the name suggests, are lights that mark the width of the vehicle. They must be turned on when it's dark or visibility is low, such as in the evening, during rain, or in foggy conditions, to make the outline of your car visible to others. The colors are generally red, yellow, or white. Daytime running lights (DRLs) are completely different—they automatically turn on when driving during the day to alert others of an approaching vehicle. Nowadays, regulations mandate that all new cars must be equipped with DRLs. Width indicator lights come on together with the headlights, while DRLs automatically light up when the car is started. In terms of design, DRLs are positioned much higher than width indicator lights and are significantly brighter. Many cars now design their DRLs to be particularly eye-catching. If the DRLs malfunction, the width indicator lights can temporarily serve as a substitute, but their brightness is far from sufficient to replace the function of DRLs.
After driving for so many years, I've noticed that many people can't tell the difference between these two lights. The most straightforward way to distinguish them is by their usage scenarios: as soon as it gets dark or when entering a tunnel, you need to manually turn on the parking lights to mark your vehicle's position; whereas daytime running lights (DRLs) automatically stay on whenever the vehicle is running, making your car highly visible to oncoming traffic even in broad daylight. The brightness difference is particularly obvious—standing in front of the car, DRLs are glaringly bright, while parking lights are much milder. In terms of design, parking lights typically use traditional bulbs or LED beads, while DRLs are often designed as full light strips. Nowadays, new car models even treat DRLs as a signature family design element. Once, when my DRL fuse blew and I temporarily used the right parking light as a substitute, it proved completely ineffective on the highway—vehicles behind couldn't clearly discern my car's width or outline at all.
Three fundamental differences: First, the functions differ - position lights are for nighttime vehicle identification, while daytime running lights (DRLs) serve as daytime safety warnings. Second, there's a tenfold difference in luminous intensity - DRLs require at least 100 lumens, whereas 30 lumens suffice for position lights. Third, color standards vary - position lights (taillights) must be red, front position lights amber or white, while DRLs are mandated to be white. I've observed that in recent years, new car models position DRLs along the hood crease lines, while position lights are embedded on the inner side of headlight clusters. Though popular in the modification scene, converting DRLs to colored lights is actually non-compliant, whereas changing position lights to ice-blue bulbs doesn't affect annual inspections. Mechanics always remind us that these two lighting systems have separate driver modules - never attempt to combine circuits for convenience during repairs.
