Parts for your 2016 Toyota Prius-Sump plug washers

2016 Toyota Prius sump plug washer — what it is and why it matters

Yes, the 2016 Toyota Prius (ZVW50, 2ZR-FXE) uses a sump plug washer. Technical sources confirm it: the Toyota Repair Manual directs refitting the engine oil drain plug with a new gasket at each oil change, and the Toyota Electronic Parts Catalog lists an aluminium crush washer for the drain plug (commonly Toyota P/N 90430-12031, 12 mm). The manual also specifies tightening the plug to around 39–40 N·m. References: Toyota TIS Repair Manual for 2016 Prius, Engine/Hybrid System – Lubrication section, Toyota Electronic Parts Catalog listing for the engine oil drain plug gasket.

On this Prius, the sump plug washer (also called a drain plug gasket) is a small aluminium crush ring that sits between the sump (oil pan) and the drain plug head. Its job is simple but critical: when the plug is torqued, the soft aluminium deforms slightly to create a reliable, oil-tight seal. That prevents weeping, drips on the driveway, and low oil level over time. On an alloy sump like the Prius runs, it also helps distribute load so the mating face doesn’t get gouged.

Best practice is to replace the washer every time the engine oil is changed. Toyota’s service procedure literally says “install the drain plug with a new gasket,” because once a crush washer has been compressed, it won’t spring back to seal perfectly again. Reusing it can lead to micro-leaks or tempt overtightening, which risks stripping threads.

• Use a quality aluminium 12 mm washer that matches the OE profile (Toyota P/N 90430-12031 or equivalent).
• Clean the sump face and plug, then torque the plug to spec (about 39–40 N·m) rather than guessing.
• Check for any seepage after the first short drive and again at the next cold start.
• If the old washer is stuck to the sump, carefully remove it without scratching the sealing face.

Owners and workshops across Australia and New Zealand will find these washers inexpensive and easy to source, and replacing them is a quick win for long-term reliability. It’s a small part that does a big job, and on a Prius that’s expected to rack up plenty of quiet kilometres, keeping the sump plug gasket fresh is a no-brainer.

Popular questions

What size and part number is the sump plug washer on a 2016 Toyota Prius?
The 2016 Prius uses a 12 mm aluminium crush washer. Toyota’s common listing for this model is P/N 90430-12031. Aftermarket equivalents are fine if they match the OE dimensions and material. If unsure, confirm against the VIN in a parts catalogue.

How often should the sump plug washer be replaced?
Replace it at every engine oil change. The washer is designed to crush once, reusing it can lead to weeping or the need to overtighten the plug. Follow the service interval in the maintenance schedule and fit a new gasket each time.

What’s the correct torque for the Prius sump plug, and can a copper washer be used?
Toyota specifies about 39–40 N·m for the 2ZR-FXE engine’s drain plug. Always verify in the service information for the exact variant. Aluminium is the OE material and seals very predictably on the alloy sump. Copper can work, but stick with aluminium to match the factory spec and feel.