Mercury Mariner high beam and low beam headlight bulbs both utilize a 9008 bulb size across the model line. The replacement chart covers 2005 through 2011 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9008 bulb is the sole headlight bulb type specified for the Mercury Mariner across all listed model years, covering both high beam and low beam positions for 2005-2011.
The 9008 is a dual-filament halogen bulb, meaning a single bulb contains two separate filaments: one rated at 65W for high beam output and one rated at 55W for low beam output.
Because both filaments are housed in one unit, the 9008 serves both the high beam and low beam functions simultaneously, which is why the same bulb size appears in both headlight positions on the Mariner.
The 9008 operates on a 12V electrical system, consistent with standard automotive voltage found in passenger vehicles.
The bulb uses a P26t base, which is a specific pin-and-collar connector type that physically determines fitment; a bulb with a different base type will not seat correctly in the socket regardless of its wattage or voltage rating.
The 9008 designation follows ANSI standards recognized in both the United States and Canada, meaning the specification reflects a regulated performance and construction standard rather than a manufacturer-specific classification.
The 9008 is also commonly cross-referenced as H13, and these designations refer to the same bulb; however, substitution should be confirmed against socket compatibility before installation.