The Pontiac Montana uses H11 and 9004 bulb sizes for both high beam and low beam headlight applications. Replacement chart data covers 1999 through 2006 production years 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 follows the ANSI standard used in the US and Canada. It is a dual-filament halogen type, meaning a single bulb contains separate filaments for both high beam and low beam functions. It operates at 12V with a wattage rating of 65W on high beam and 45W on low beam, and it uses a P29t base.
The H11 bulb follows the ECE standard, which is recognized across Europe and internationally, and is also approved for use in the US. Unlike the 9004, it is a single-filament halogen bulb, meaning it serves only one lighting function per unit. It operates at 12V and 55W, and it uses a PGJ19-2 base.
Because the 9004 is a dual-filament bulb and the H11 is a single-filament bulb, the two types are not interchangeable. Vehicles using H11 for both high and low beam functions require two separate bulbs per headlamp assembly, while vehicles using the 9004 require only one bulb per assembly to cover both functions.
The Pontiac Montana used the 9004 bulb for both high and low beam headlights across the 1999-2004 model years, with no variation in bulb type during that period.
The 2005 Pontiac Montana introduced a headlamp configuration split, where vehicles equipped with a 2-headlamp system retained the 9004 bulb, while vehicles equipped with a 4-headlamp system used the H11 bulb for both high and low beam positions.
For the 2006 model year, the Montana specification lists only the H11 bulb for both high and low beam headlights, with no 9004 variant noted for that year.
The base types of the 9004 (P29t) and H11 (PGJ19-2) are physically distinct, which reinforces that these bulbs cannot be substituted for one another without modification to the socket or wiring.
On 4-headlamp configurations of the 2005 Montana, the use of single-filament H11 bulbs means the high beam and low beam functions are handled by separate dedicated bulbs rather than a single dual-filament unit.