I was trying to put a trailer hitch on a mazda CX-9 when I noticed the difference. It had a very small gauged wire running some huge taillights. Bright too. This was a major thorn in my side as I had to use the adapter and wire a hot from the battery back because the taillight wire wouldn't carry enough amperage to power the trailer lights. I can see this would save weight, save copper, and save fuel as they use less power. They are also very vivid and shine through weather/splash/spray/fog better. The truckers at work all use them as the DOT cannot assume that at least one light will be out as they did before. I do not have them on my car hauler yet but I will.
Got a string of em on the gutter right now.