Polaris 600 XC SP Brake Bulb Size

The Polaris 600 XC SP uses 3157 and 921 bulb sizes for brake applications, with these specifications representing the distinct bulb configurations required for this snowmobile model. The replacement chart covers vehicle production spanning 1999 to 2005, detailing the bulb size requirements across those manufacturing years.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2005	3157
1999-2004	921

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

Other Locations

Additional Notes

The 921 bulb is a single-filament wedge type (T15) rated at 12V and 16W under the ANSI standard applicable in the US and Canada. It served as the brake bulb for the Polaris 600 XC SP across the 1999-2004 model years.
The 3157 is a dual-filament wedge bulb (T25) rated at 12V with a 27W high filament and a 7W low filament, also conforming to the ANSI standard for the US and Canada. The 2005 Polaris 600 XC SP uses this bulb for the brake function.
The dual-filament design of the 3157 means it carries two separate circuits within one bulb, allowing it to serve both a brighter brake function and a dimmer running light function simultaneously, which differs fundamentally from the single-filament 921.
The T25 envelope of the 3157 is physically larger than the T15 envelope of the 921. These two bulbs are not interchangeable, as differences in size, wattage, and filament count make one a direct substitution risk for the other.
The 2005 model year represents a change in brake bulb specification for the 600 XC SP, shifting from the 921 to the 3157. Using a 921 in a socket designed for a 3157 would result in an incorrect fit and incompatible electrical characteristics.