Used for: Back Up Reverse Light Bulb
Used for: Parking Light Bulb, Turn Signal Light Bulb Front
Used for: Side Marker Light Bulb Front
Used for: Turn Signal Light Bulb Rear
Used for: Interior Door Light Bulb, Trunk or Cargo Area Light
This page covers bulb size information for the 2018 Lexus RX 350 and is organized by lighting position so you can quickly verify the correct replacement bulb before you buy. Because exterior and interior lamps can differ by location, checking the exact socket on your vehicle is the safest way to match the right fit.
For the 2018 Lexus RX 350, the listed bulb positions include back up reverse light, trunk or cargo area light, interior door light, front turn signal, parking light, rear turn signal, and front side marker light. Use this page as a reference when replacing a single bulb or comparing both sides of the vehicle to keep lighting consistent.
Fitment can vary by trim, lighting package, market, and body style, so the same 2018 Lexus RX 350 may not use identical bulbs in every region or configuration. Some lamps may be halogen while others are LED-based, and aftermarket LED conversions can change the bulb type, brightness, or warning behavior. Before ordering, it is smart to inspect the installed bulb and confirm the base style, especially if the vehicle has been modified or if a previous owner replaced factory parts with non-original components.
The listed back up reverse light bulb size for the 2018 Lexus RX 350 is 921.
The trunk or cargo area light uses bulb size 168 on the 2018 Lexus RX 350.
The interior door light bulb size listed for the 2018 Lexus RX 350 is 168.
The front turn signal light bulb size is 7444NA.
The parking light bulb size listed for the 2018 Lexus RX 350 is 7444NA.
The rear turn signal light bulb size listed for the 2018 Lexus RX 350 is 7440A.
The front side marker light bulb size listed for the 2018 Lexus RX 350 is 168NA.
Not always. Trim level, lighting package, market, and body style can affect bulb fitment, so it is best to confirm the bulb in your specific vehicle before purchasing replacements.
In many cases, yes, but the replacement must still fit the socket and function correctly. LED conversions can change beam pattern, brightness, or cause warning messages, so compatibility should be checked carefully.
Checking the installed bulb helps confirm the exact base and size, which is especially useful if the vehicle has aftermarket parts, a prior repair, or a lighting package that differs from the standard setup.
It is often a good idea for paired exterior lights such as turn signals or parking lights, because matching bulbs help keep color and brightness even from side to side.
Use the bulb currently installed in your vehicle as the final reference, since some RX 350 configurations may differ from the standard listing on this page.
