The INFINITI I30 brake light uses 7440 and 1157 bulb sizes for the rear lighting system. Data for the specific components covers the period from 1996 through 2001.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The INFINITI I30 brake light circuit uses two distinct bulb types across its production run. The 7440 appears in the 2000-2001 model years, while the 1157 serves the 1996-1999 model years.
The 7440 is a single-filament T20 wedge bulb rated at 12V and 21W. Its wedge base design means it locks into the socket by friction rather than a bayonet twist mechanism.
The 1157 is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with a 21W/5W filament configuration. The dual-filament design allows one circuit to handle braking and a separate lower-power circuit to handle running light functions simultaneously.
The 7440 and 1157 are not interchangeable despite sharing a 21W primary wattage rating. The 7440 uses a wedge base while the 1157 uses a BAY15d bayonet base, making the socket types physically incompatible.
The center high mount stop light (CHMSL) on the INFINITI I30 uses a different bulb than the main brake lights across all six model years covered in the specifications.
The CHMSL circuit alone draws on four distinct bulb types across the 1996-2001 model range, specifically the 1156, 921, 7440, and 168.
The 1156 is a single-filament bulb with a BA15s bayonet base rated at 12V and 21W. It shares the same wattage as the 7440 but uses a bayonet base rather than a wedge base, making the two non-interchangeable.
The 921 is a T15 wedge bulb rated at 12V and 16W. It occupies a wattage range between the low-power 168 and the higher-output 7440 and 1156 types found elsewhere in the I30 brake lighting system.
The 168 is a miniature T10 wedge bulb rated at 12V and 4.9W. Its low wattage relative to all other bulbs in these specifications reflects its use in the 2001 CHMSL position, where a lower light output is sufficient for the supplemental stop light function.
All five bulb types listed across these specifications conform to ANSI standards applicable in both the United States and Canada, indicating standardized electrical and physical tolerances across the range.