The Maserati 228i headlight bulb specifications include an H4651 size for high beam and H4652 size for low beam applications. The replacement chart covers 1989 to 1990 model production years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H4651 and H4652 are ANSI-standardized sealed beam units used in both the high beam and low beam positions of the Maserati 228i across the 1989-1990 model years.
Both bulb types conform to the 4x6-inch rectangular sealed beam format, a standardized size regulated under ANSI specifications for the United States and Canadian markets.
A sealed beam unit integrates the filament, reflector, and lens into a single fused assembly, meaning the entire unit is replaced rather than an internal bulb component.
The H4652 is a variant of the H4651, with both types sharing the same 4x6-inch rectangular form factor and 12-volt operating voltage, though they serve distinct beam functions and are not interchangeable with each other.
The 12-volt rating of both units is consistent with standard automotive electrical systems of that period.
Because the H4651 and H4652 are ANSI-standardized formats rather than proprietary designs, physically compatible replacements from multiple manufacturers are generally available, provided they meet the same ANSI designation.