The Mack Pinnacle headlight bulb size chart specifies high beam and low beam bulb options, with high beam sizes of 9004 and 9005XS, and low beam sizes of 9004 and 9006XS for this truck model. The replacement chart covers vehicle production years from 2011 to 2017 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9004 bulb is a dual-filament halogen type operating at 12V with a P29t base, rated at 65W on the high beam filament and 45W on the low beam filament. Its dual-filament design means a single bulb handles both high and low beam functions within a two-headlamp system.
The 9005XS and 9006XS are single-filament halogen bulbs sharing a straight 180-degree base configuration. The 9005XS is rated at 65W and serves the high beam function, while the 9006XS is rated at 55W and serves the low beam function in four-headlamp systems.
All three bulb types, the 9004, 9005XS, and 9006XS, conform to ANSI standards applicable in the United States and Canada.
The Mack Pinnacle uses two distinct headlamp configurations across the 2011-2017 model years: a two-headlamp setup and a four-headlamp setup. The correct bulb type is determined entirely by which configuration is present on the vehicle.
In the two-headlamp configuration, the 9004 bulb serves as both the high beam and low beam source due to its dual-filament construction. Substituting a single-filament bulb in this application would result in the loss of one beam function.
In the four-headlamp configuration, the high and low beam functions are handled by separate dedicated bulbs, the 9005XS and 9006XS respectively. These two bulbs are not interchangeable with each other, as they differ in wattage and beam function.
The 9005XS and 9006XS are straight-base variants of the more common 9005 and 9006 bulbs. The "XS" designation indicates the straight 180-degree base, which differs physically from the standard angled base, making cross-substitution between XS and non-XS versions incompatible.