said by Sylvania :
Q) How long do the headlights last?
A) The life of any halogen bulb varies based on vehicle type, vehicle voltage, amount of time the bulb is on, road conditions, proper installation, and correct application. The average life of SilverStar® headlights is approximately one year. With our SYLVANIA SilverStar® products, the primary goal is to offer the brightest, whitest light. Research has shown SilverStar® headlights improve driver visibility and reaction time. However, since our SilverStar® headlights are up to 35% brighter and our SilverStar® ULTRA headlights are up to 50% brighter than standard halogen, they may have a shorter life span compared to our other products. We offer a wide variety of products to satisfy customer needs including brightness, durability, color options and increased visibility. We recommend evaluating your headlights annually as part of your regular vehicle maintenance.
There are three types of Silverstar bulbs. The brighter the bulb, the shorter the life. Some only last about a year.
See - »www.sylvania.com/en-us/products/···cts.aspx