What size is the oil drain plug on a Subaru?
The drain plug on most Subaru engines uses a 14 mm hex head with an M14x1.5 thread. This is the standard for many contemporary Subarus across multiple engine families.
In this article we’ll break down what that means for typical service, note common variations by model and year, explain how to verify the correct size for your car, and cover the recommended torque and gasket practices to ensure a proper seal during oil changes.
Standard size and thread
For the majority of Subaru engines, including common EJ, FA, and FB families, the oil drain plug follows a consistent sizing pattern. The plug is designed to be removed with a 14 mm wrench or socket, and the thread is a metric M14x1.5. This pairing is widely used and familiar to many DIY mechanics and technicians.
Before performing a drain plug change, it’s helpful to confirm these specifics on your exact model-year, as there can be exceptions or aftermarket replacements. The following list highlights the core details most Subaru owners will encounter.
- Head size: 14 mm hex (fits a 14 mm wrench/socket)
- Thread size: M14 x 1.5
- Seal/gasket: copper or aluminum crush washer is commonly used; replace it at each oil change
- Torque specification: typically around 20–30 Nm (approximately 14–22 ft-lb), depending on model and gasket type
- Special notes: some early or specialized models may have variations; always verify via the owner's manual or service manual for your exact engine code
These details cover the essential size, thread, sealing method, and tightening torque you’ll typically encounter when servicing Subaru oil pans.
How to verify for your model
Because Subaru engines span several generations and different markets, a quick confirmation helps prevent cross-model guesswork. Start with the most reliable sources and then inspect the plug if needed.
Check official documentation
Consult your owner’s manual or the official service manual for your specific model and year. Look for the oil pan drain plug specifications, including head size, thread type, and torque values.
Inspect the existing drain plug
Remove the plug carefully with a 14 mm wrench or socket if it fits. If it doesn’t, do not force it—there may be a different size or a counterfeit/aftermarket plug installed. In that case, measure the head with a caliper or use a plug that matches the thread pitch and diameter you observe.
Consult a dealership or trusted mechanic
If you’re unsure, a Subaru dealership’s service department or a qualified auto technician can confirm the correct drain plug size and torque for your exact engine code and model year.
Summary
For most Subaru engines, the oil drain plug size is standard at a 14 mm hex head with an M14x1.5 thread, typically sealed with a copper or similar washer and torqued to roughly 20–30 Nm. Always verify against your specific model-year with the official manual or a dealer if you’re unsure, as variations do exist between different engines and production years.
