Q: How Long Are Headlights Bulbs Supposed to Last

The lifespan of a headlight bulb in a vehicle is not possible to predict with much accuracy. There are just too many variables affecting how long your bulbs will last.

These factors include:

• Wattage rating of the lights. Brighter, hotter lights usually have shorter lives.

• Type of lights. HID lights can last several times longer than halogen bulbs.

• Quality of manufacturing. Not all bulbs are created equal. Bulbs with superior design and build quality can be expected to outlast lower quality items.

• How often they are turned on and off. Every time a lightbulb is turned on it heats up and expands. And, of course, when turned off it cools down and contracts. This is called thermal cycling and affects a component’s usable service life.

• Vehicle electrical system stability. Variations in voltage from a vehicle’s charging system, especially when it goes too high, shortens bulb life.

• Roughness in use. A vehicle that sees regular driving on rough pavement or washboard dirt roads can expect shorter bulb life than a comparable vehicle driven over smooth roads.

Manufacturer’s have a target in mind when they design and build a bulb. A certain average number in hundreds of hours of operation before failure. But with automotive light bulbs, they don’t always share that information with us. So my recommendation is to purchase the best quality bulbs you can locate. Use original equipment parts or a recognizable major name brand of lamps for your vehicle. A burned out bulb on your vehicle is more than an inconvenience; it’s also a safety hazard and can get you a ticket. If you run into any problems with your headlamps, a certified mechanic can inspect and replace your lights if necessary.