The Lexus GS430 high beam headlight uses a 9005 bulb size, while low beam headlights require D4S, 9006, or D2R bulb sizes depending on configuration. The replacement chart covers 2001 through 2007 model 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 Lexus GS430 uses the 9005 bulb for the high beam headlight across all model years from 2001-2007. This is an ANSI-standard single-filament halogen bulb rated at 12V and 65W, fitted with a P20d base.
The 9006 halogen bulb, rated at 12V and 55W with a P22d base, serves as the low beam light source in GS430 models from 2001-2004 equipped with halogen capsule headlamps. Although the 9005 and 9006 share a similar physical form, their base configurations differ, making them non-interchangeable despite a common misconception that they are compatible.
For 2001-2004 GS430 vehicles fitted with HID headlamps, the low beam position uses the D2R bulb instead. The D2R is an ECE-standard xenon discharge bulb operating at 85V and 35W with a P32d-3 base, designed specifically for reflector-type housings. It requires a separate external ignitor to initiate the arc discharge.
From 2005-2007, the Lexus GS430 low beam specification shifts exclusively to the D4S bulb, a mercury-free HID type operating at 42V and 35W with a P32d-5 base. The D4S is engineered for projector-type housings and is not interchangeable with the D2R used in earlier model years, as the two bulbs differ in base type, internal construction, and housing compatibility.
The D4S and D2R bulbs share the same 35W power rating but operate at substantially different voltages, 42V and 85V respectively, reflecting distinct ignition and ballast requirements that make their electrical systems incompatible with one another.
The transition from D2R to D4S in the 2005-2007 low beam specification also reflects a shift from reflector-type to projector-type housing design, as each HID bulb type is optically matched to a specific housing geometry and cannot perform correctly in the other.