The Acura RL side marker utilizes a 168 bulb size for the lighting components located on the exterior of the vehicle. Data for 168 bulbs covers the period from 1996 through 1998.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The front side marker position on the Acura RL uses two distinct bulb types across its model years, with the 168 fitted to 1996-2008 models and the 194NA fitted to 2009-2012 models.
The 194NA is a T10 miniature wedge bulb rated at 12V and 3.78W. Its defining characteristic is a natural amber glass envelope, which produces the amber color required for side marker use without relying on a colored lens or housing.
The 168 is also a T10 miniature wedge bulb and shares the same ANSI-standard base as the 194NA, but it operates at a slightly higher wattage of 4.9W and has a clear glass envelope rather than amber-tinted glass.
Because the 194NA and 168 share the T10 wedge base, they are physically interchangeable in terms of socket fitment. However, the 194NA carries its amber tint within the glass itself, so substituting a clear 168 in a position that depends on the bulb for amber color output would alter the emitted light color.
The rear side marker position on the Acura RL (1996-1997) uses the 168 bulb, the same type specified for the front side marker during that same period.
From 1999-2004, the rear side marker on the Acura RL uses the 7443, a T20 dual-filament wedge bulb rated at 12V with a 21W main filament and a 5W secondary filament.
The 7443 is a T20 wedge bulb, which uses a physically larger base than the T10 used by the 168 and 194NA. The two base sizes are not interchangeable.
The dual-filament design of the 7443 allows a single bulb to serve two independent lighting functions, with the 5W filament typically handling the steady marker function and the 21W filament handling a brighter signaling or braking function.