Chevrolet Tiltmaster (W-Series) Side Marker Bulb Size
Chevrolet Tiltmaster (W-Series) front and rear side marker bulbs utilize 194 and 1157 sizes. The replacement chart covers vehicle production spanning 1986 to 2001.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Chevrolet Tiltmaster (W-Series) front side marker position uses two distinct bulb types across its production span, with the 1157 specified for 1986-1988 and the 194 specified for 1992-2001.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, operating as a single-filament light source with a wedge-style base that requires no locking mechanism for retention.
The 1157 is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with a 21W high filament and a 5W low filament, making it capable of serving both a primary and secondary lighting function within a single housing.
Both the 194 and 1157 are ANSI-standardized bulbs recognized in the United States and Canada, meaning their physical and electrical characteristics conform to a defined industry specification rather than a proprietary format.
The BAY15d base of the 1157 features two offset pins at different heights, a design that prevents incorrect insertion and distinguishes it physically from single-filament bayonet bulbs with symmetrical pins.
The 194 and 1157 are not interchangeable. The wedge base of the 194 and the bayonet base of the 1157 are mechanically incompatible, and their wattage ratings differ substantially.
For the rear side marker position, the 1988 Tiltmaster (W-Series) uses the 194, while the 1986-1987 model years use the 1157, indicating that the rear and front positions did not share the same bulb type in 1988.
In 1988, the front and rear side marker positions of the Tiltmaster (W-Series) specify different bulb types, with the front requiring the 1157 and the rear requiring the 194.