The Maserati 430i uses a P21W bulb size for the front turn signal and 1156 bulb size for the rear turn signal. The replacement chart covers 1989 to 1990 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Maserati 430i uses two distinct bulb standards across its front and rear turn signal positions for the 1989-1990 model years.
The front turn signal on the Maserati 430i uses the P21W bulb, which follows the ECE standard adopted in Europe and worldwide markets.
The rear turn signal uses the 1156 bulb, which follows the ANSI standard used in the United States and Canada.
Despite carrying different part designations, the P21W and 1156 are electrically identical, both operating at 12 volts with a 21-watt output and a single filament.
Both bulbs share the BA15s bayonet base, a single-contact base type where the "s" denotes a single pin offset to one side of the base.
The shared BA15s base between the P21W and 1156 means the physical mounting interface is the same, though the differing certification standards reflect regional regulatory requirements rather than electrical differences.
The single-filament design of both bulbs means each serves only one lighting function, as opposed to dual-filament bulbs that combine two functions such as turn signal and brake light in one unit.
The fitment is consistent across both the 1989 and 1990 model years, with no variation in bulb specification between those two years for either the front or rear positions.