Are most oil drain plugs the same size?

No—most oil drain plugs are not the same size. While a handful of sizes are common, thread diameter, pitch, and washer type vary by vehicle make, engine, and oil pan design. Always confirm the exact specification in your owner’s manual or parts catalog before buying or installing a plug.

What actually varies between oil drain plugs

Despite looking similar, oil drain plugs differ in several critical dimensions and features that affect fit, sealing, and torque. Understanding these variables helps you avoid stripped threads, leaks, or overtightening.

• Thread diameter and pitch (for example, M14 x 1.5 vs M12 x 1.25 vs 1/2″-20 UNF).
• Head size and style (common hex sizes include 13, 14, 15, 17, 19 mm; some use internal hex or square).
• Length and shoulder design, which influence thread engagement and sealing.
• Sealing method (crush washer, bonded rubber gasket, tapered threads on some older pans).
• Material and features (steel or aluminum, magnetic tip, coated threads).

Treat the plug as a matched system with its washer and pan: mixing sizes or washer types often leads to leaks or damage.

Common sizes you’ll encounter

The sizes below are frequently used, but there is no universal standard across brands or model years. Always verify by VIN or service documentation.

• Metric: M12 x 1.25 (seen on some Toyota/Nissan), M12 x 1.5, M12 x 1.75 (less common).
• Metric: M14 x 1.5 (very common across Honda, VW/Audi, Ford, GM, Mazda, BMW among others), M14 x 1.25 (select models).
• Metric: M16 x 1.5 (various trucks and larger engines), M18 x 1.5 (some European and truck applications), M20 x 1.5 (common on many Subaru models).
• SAE/Imperial: 1/2″-20 UNF and 5/8″-18 on some older U.S. vehicles; tapered NPT is rare for modern engine oil pans.
• Washers: typically 12, 14, 16, 18, or 20 mm inner diameter to match the plug’s thread size; materials include aluminum, copper, or bonded rubber/steel.

Even within one brand, engines and generations can differ. For example, a manufacturer might use M12 x 1.25 on one engine and M14 x 1.5 on another in the same model line.

How to identify the correct drain plug for your vehicle

Because visual inspection is unreliable, use the following steps to confirm the exact fit before you remove or replace the plug.

1. Check the owner’s manual or factory service manual for the drain plug spec and torque.
2. Use the VIN in an OEM parts catalog or reputable aftermarket lookup to get the exact thread size, pitch, and washer part number.
3. If measuring, use calipers for diameter and a thread pitch gauge (metric vs SAE) to confirm pitch; don’t rely on the hex head size.
4. Match the washer: the inner diameter must correspond to the plug size (e.g., 14 mm washer for an M14 plug) and the material should match the service spec.
5. Cross-check the torque spec once you’ve identified the plug to avoid stripping aluminum pans.

Verifying beforehand prevents cross-threading and ensures you have the correct replacement washer ready for reassembly.

Torque and washer guidelines

Torque and sealing practices vary with plug size and pan material. Over-tightening is a common cause of stripped threads and leaks.

• Typical torque ranges (always defer to the vehicle spec):
  – M12 plugs: roughly 15–25 lb-ft (20–34 N·m)
  – M14 plugs: roughly 20–30 lb-ft (27–40 N·m)
  – M16–M20 plugs: roughly 25–35+ lb-ft (34–47+ N·m)
  Aluminum pans often specify the lower end of these ranges.
• Always replace single-use crush washers at each oil change; aluminum and copper are common. Bonded rubber/steel washers may be reusable if specified, but inspect for deformation.
• Clean mating surfaces and threads; lightly oil the washer if recommended by the manual. Do not use thread sealant unless the service procedure calls for it.

If threads are damaged, consider a threaded insert (Heli-Coil or Time-Sert) for a permanent repair rather than oversized or self-tapping “fix” plugs, which are temporary at best.

What about “universal” or quick-drain valves?

Aftermarket quick-drain valves (e.g., Fumoto, ValvoMax) are convenient but are not universal: each model is offered in specific thread sizes and pitches. You must select the unit that matches your plug specification and washer type.

Bottom line

There is no one-size-fits-all oil drain plug. A few sizes—especially M14 x 1.5—are common, but variability across engines and model years is significant. Confirm the thread size, pitch, and washer spec by VIN or manual, use the correct torque, and replace the crush washer to ensure a leak-free service.

Summary

Most oil drain plugs are not the same size. Common threads include M12 x 1.25, M14 x 1.5, M16 x 1.5, M18 x 1.5, M20 x 1.5, and some SAE sizes on older vehicles. Differences in pitch, head size, washer type, and torque mean you should verify the exact spec for your vehicle before service to avoid leaks or damage.

How do I know what size drain plug I have?

To ensure you choose the correct sink waste plug fitting or size, measure the diameter of the drain mesh or the underside of your current plug.

Are oil drain plugs universal?

No, oil drain plugs are not universal, but specific “universal” replacement plugs are available that fit a range of common sizes, especially for repairing damaged threads. Original drain plugs vary in size, thread pitch, and design depending on the make, model, and year of the vehicle, so you must find the correct one for your specific car. 
Why There Isn’t One Universal Plug

• Different Vehicle Designs: Opens in new tabEach vehicle has a different design for its oil pan, which dictates the type of drain plug needed. 
• Thread Variations: Opens in new tabPlugs come with various SAE and metric thread sizes, thread pitches, and lengths. 
• Gasket Types: Opens in new tabSome plugs use built-in gaskets, while others require a separate crush washer or O-ring. 

Finding the Right Plug

1. Check Your Owner’s Manual: Opens in new tabYour vehicle’s owner’s manual is the best source for information on the correct drain plug. 
2. Consult an Automotive Parts Database: Opens in new tabYour local auto parts store can use their application search to find the correct plug for your specific car, make, model, and year. 
3. Identify Stripped Threads: Opens in new tabIf the original plug or pan threads are stripped, you can purchase an oversized or “universal” repair plug designed to re-thread the hole. 

Types of “Universal” Plugs

• Adjustable Range Plugs: Opens in new tabSome repair plugs are designed to fit a range of common sizes, such as 1/2 inch to 3/4 inch or M12 to M18. 
• Threadless Plugs: Opens in new tabSpecial “threadless” plugs use a magnetic design and rubber seal to work with stripped or damaged oil pans, like the Eco-Plug system. 

Are all oil drain plugs the same size?

Generally, oil drain plugs do only come in a couple of sizes. A given car maker would generally use the same size plug in all their cars, it’s cheaper and easier that way. Some oil plugs are marked with sizes on the surface, like M12x1. 5, M14x1.

What size socket is a standard oil drain plug?

There isn’t a single socket size for all oil plugs; the correct size depends on your vehicle’s make, model, and year. Common sizes include 17mm and 14mm for many Japanese and European cars, but you might need to check your vehicle’s specifications or visit an auto parts store for help. A 6-point socket is recommended for better grip to avoid stripping the bolt head. 
How to find the right socket size

1. Check your vehicle’s manual: The most reliable way is to consult your car’s owner’s manual to find the specific drain plug size. 
2. Identify the head type: Most drain plugs have a hex-shaped bolt head. 
3. Measure the bolt head: If you have a socket set, try a few sizes to see which one fits snugly. 
4. Consult an auto parts store: Bring the vehicle information to an auto parts store, and they can look up the specific size for you. 
5. Consider common sizes: While not universal, many Japanese and European cars use metric sizes, with 17mm and 14mm being common. 

Tips for changing the oil plug

• Use a 6-point socket: This type of socket is more effective at gripping the bolt and prevents the head from getting rounded off. 
• Use a 3/8-inch drive socket and ratchet: This is a common size for most DIY oil changes. 
• Have a replacement plug ready: If the old drain plug is worn or stripped, you’ll need a new one to replace it.