Standard WRX oil drain plug size is M20 x 1.5 with a 14 mm hex head.
Across most WRX generations—from early EJ-powered models to the current FA/FB-era cars—the drain plug size remains consistent. Always check your owner's manual or the service manual for your exact year to confirm torque specifications and any year-specific notes.
Standard size and thread
Key dimensions you should know when shopping for a replacement or checking your plug.
- Thread size: M20 x 1.5
- Drain plug hex size: 14 mm
- Plug type: standard oil drain plug (magnetic variants are common)
- Typical installation torque: about 29–33 Nm (22–24 ft-lb). Always verify with the manual for your exact year and engine
In practice, using an M20 x 1.5 threaded drain plug with a 14 mm wrench is the reliable baseline for most Subaru WRX models, and you should torque it to the manufacturer’s specification when refilling oil.
Model variations and verification
While the size is broadly consistent, it's important to confirm for your specific model year and engine family.
- Most WRX engines (including EJ and FA/FB families) use M20 x 1.5 drain threads
- The standard hex head remains 14 mm across these generations
- Always verify the exact torque spec and any year-specific notes in your owner's manual or service manual
If you’re unsure, consult a Subaru dealer or reference the official service manual for your VIN to confirm any variations or special seals required for your plug.
How to remove and reinstall
Following a safe procedure ensures proper drainage and sealing during an oil change.
- Warm engine slightly and park on level ground; place a drain pan beneath the oil pan drain plug.
- Use a 14 mm socket or wrench to loosen the drain plug, allowing oil to drain completely.
- Clean the plug and sealing surface; inspect the crush washer or gasket and replace if needed.
- Reinstall the plug by hand, then torque to the manufacturer’s specification (commonly around 29–33 Nm).
- Refill with the correct oil type and amount; check for leaks after a short idle, and recheck the plug torque if necessary.
Note: If your plug uses a crush washer, replace it with a new one to ensure a proper seal.
Summary
For the Subaru WRX, the oil drain plug typically uses M20 x 1.5 threads and a 14 mm hex head, with a common torque range around 29–33 Nm. This sizing covers most WRX models across generations, but always verify the exact specification in your owner's manual or service manual for your year and engine. Using the correct size helps prevent stripping and ensures a proper seal during oil changes.