Lighting upgrades are also popular, sometimes for looks, and sometimes because it seems the original headlights do not put out sufficient light. Headlights can be upgraded or supplemented in a variety of ways. Taillight mods may not have any functional benefits, but they have been popular since the days of customizing Model Ts.

When it comes to visibility, there are three factors to consider. The first is the total brightness. The second is the color. Blue light is more likely to create glare for oncoming drivers or scatter in fog, while yellow or amber lights often carry further in such weather than other colors. The third characteristic is the beam pattern. The way the light leaves a bulb is not distributed evenly. Most headlights ...

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