Ski-Doo Formula S Tail Light Bulb Size

The Ski-Doo Formula S tail light utilizes a single 1157 bulb size for illumination across all listed snowmobile versions. Available information covers the specific production range from 1995 through 2000.

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	US Type	EU Type	Shop
1995-2000	1157	P21/5W	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157	Check Price
ECE standard (Europe & worldwide). Dual-filament signalling bulb with BAY15d bayonet base. 12V, 21W/5W.	P21/5W	Check Price

Other Locations

Additional Notes

The 1157 is the tail light bulb size specified for the Ski-Doo Formula S across all listed model years from 1995-2000.
The 1157 is an ANSI-standardized bulb type recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical standards shared across those markets.
The 1157 is a dual-filament bulb, which means it contains two separate filaments within a single envelope, allowing it to serve two distinct lighting functions from one unit.
The bulb operates on a 12-volt electrical system and carries a wattage rating of 21W on the high filament and 5W on the low filament, corresponding to its brighter and dimmer operating states respectively.
The 1157 uses a BAY15d bayonet base, a two-pin offset base type where the two pins are positioned at different heights to ensure the bulb can only be inserted in the correct orientation.
Because the BAY15d base uses offset pins, a single-filament bulb sharing the same general base style but with equal-height pins, such as the BA15d, is not a compatible substitute despite superficial similarities.