Fiat 500L front fog light uses H11 bulb size while rear fog light requires 921 bulb size for replacement. The chart covers 2014 to 2020 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 Fiat 500L uses two distinct bulb types across its fog light system: the H11 for front fog lights and the 921 for rear fog lights, covering all model years from 2014-2020.
The H11 is a single-filament halogen bulb operating at 12V and 55W, fitted with a PGJ19-2 base, and is governed by ECE standards with approval for use in both European and US markets.
The 921 is a wedge-style bulb of the T15 form factor, rated at 12V and 16W, and follows ANSI standards applicable to the US and Canadian markets.
The wattage difference between the two fog light bulbs is substantial: the front H11 draws 55W while the rear 921 draws 16W, reflecting the differing functional demands of front and rear fog lighting.
The H11's PGJ19-2 base is a keyed, projector-style connector, which physically prevents substitution with visually similar single-filament halogen bulbs that carry incompatible base types.
The 921 wedge base design allows it to be seated without a separate locking connector, as the bulb is held in place by tension within the socket itself.
The Fiat 500L front fog light position calls for the H11 across all seven model years in the specifications, indicating no variation in front fog bulb fitment throughout the 2014-2020 production span.
The rear fog light position on the Fiat 500L likewise shows no variation, with the 921 specified uniformly across 2014-2020.
Because the H11 and 921 use entirely different base types and wattage ratings, the two bulbs are not interchangeable between the front and rear fog light positions.