What size bolt is my oil drain plug?

The size of an oil drain plug varies by vehicle; there isn’t a single standard. Most passenger cars use metric plugs such as M12x1.25, M12x1.5, M14x1.5, or M14x1.25 (with socket head sizes commonly 14mm, 17mm, or 19mm), while some trucks and Subarus use larger M16 or M20 threads. The surest answer comes from your owner’s manual or an OEM parts lookup using your VIN, or by measuring the plug’s thread diameter and pitch with a caliper and thread gauge.

Why there isn’t one universal size

Automakers choose drain plug sizes based on engine design, oil pan material (steel, aluminum, or plastic), and sealing method (crush washer, bonded washer, O-ring, or one-time-use plastic plug). Even within a brand, sizes can differ by engine and model year. That’s why visual inspection, measurement, or an OEM lookup is more reliable than guessing from the socket size alone.

Common drain plug sizes by brand and segment

The following roundup highlights patterns technicians encounter often. It’s meant to guide expectations, not replace a vehicle-specific lookup, because there are exceptions.

• Honda/Acura: Frequently M14x1.5 with a 17mm hex head; uses a 14mm crush washer; many models spec around 29 lb-ft (39 Nm).
• Toyota/Lexus: Commonly M12x1.25 on many older models and M14x1.5 on newer ones; socket heads often 14mm or 14/17mm depending on plug; crush washer required.
• Nissan/Infiniti: Often M12x1.25; head sizes typically 14mm or 17mm; uses crush washer.
• Subaru: Widely M20x1.5 with a 17mm head on late models; uses a 20mm crush washer; typical torque about 31 lb-ft (42 Nm).
• Mazda: Commonly M14x1.5; 17mm head; crush washer.
• Hyundai/Kia: Frequently M14x1.5; 17mm head; crush washer.
• Ford: Mixed; many modern applications M14x1.5; some older domestics use SAE sizes (e.g., 1/2-20 UNF) or captive-seal plugs; verify by engine.
• GM/Chevrolet/GMC/Buick/Cadillac: Often M14x1.5 or SAE (1/2-20) on older engines; some trucks vary by oil pan design.
• Chrysler/Jeep/Ram/Dodge: Commonly M14x1.5; some older SAE variants; trucks may differ by engine and pan material.
• VW/Audi: Frequently M14x1.5 with 19mm or internal hex; many newer plastic pans use a one-time-use plastic plug with O-ring (specific part, do not substitute).
• BMW/MINI: Often M12x1.5 or M14x1.5 with internal hex; crush or bonded washer depending on pan.
• Mercedes-Benz: Commonly M14x1.5 with sealing washer; some models favor oil extraction and may have different plug styles.
• Volvo: Frequently M14x1.5 with crush washer; verify by engine code.
• Motorcycles/ATVs: Often M12x1.5 or M14x1.5, but vary widely; many require specific washers and low torque.

If your vehicle appears above, treat these as common patterns, not guarantees; confirm with your manual, a VIN-based parts lookup, or by measuring your existing plug.

How to identify your exact oil drain plug size

The most reliable method is to verify using documentation or precise measurements. Follow these steps to avoid cross-threading or leaks.

1. Check the owner’s manual or service manual: Look for the oil drain plug size and torque spec; some manuals list washer size as well.
2. Run an OEM parts lookup using your VIN: Manufacturer sites and reputable parts catalogs will return the exact plug and washer part numbers and thread specs.
3. Measure your existing plug: Use a digital caliper to measure the major thread diameter (e.g., ~12.0 mm for M12, ~14.0 mm for M14, ~20.0 mm for M20).
4. Determine thread pitch: Use a metric thread pitch gauge to find 1.25, 1.5, etc. In a pinch, measure 10 mm of threads and count peaks (15 peaks ≈ 1.5 pitch).
5. Identify the sealing method: Note if there’s a crush washer (flat copper/aluminum), bonded washer, O-ring, or a one-time-use plastic plug that must be replaced every change.
6. Confirm socket/drive style: External hex (common), internal hex/Allen, Torx, or plastic bayonet-style on some European plastic pans.
7. Match the washer: Washer inner diameter must match the plug size (e.g., 12 mm washer for M12 plug). Replace it at each oil change unless the plug has an integrated seal.

Completing these checks ensures the correct plug and washer, proper sealing, and the right torque, preventing stripped threads and leaks.

Tools and small parts that make it easy

Having the right tools helps you identify and service the plug correctly and avoid overtightening.

• Digital caliper (0–150 mm) for measuring thread diameter and washer.
• Metric thread pitch gauge to verify 1.25 vs 1.5, etc.
• Quality metric socket set (14, 17, 19 mm common) and internal hex/Torx bits as needed.
• Torque wrench (inch-pound and foot-pound ranges) to hit spec accurately.
• New crush/bonded washer or OEM one-time-use plug as specified.
• Drain pan, gloves, rags, and brake cleaner for cleanup.

With these basics, you can confidently identify your plug size and complete an oil change to OEM standards.

Typical torque ranges and washer guidance

Torque varies with thread size and oil pan material; always verify the exact OEM spec for your vehicle. The ranges below reflect common manufacturer guidance for steel or cast aluminum pans with crush washers.

• M12 plugs: roughly 20–25 lb-ft (27–34 Nm).
• M14 plugs: roughly 25–33 lb-ft (34–45 Nm).
• M16/M18 plugs: roughly 28–36 lb-ft (38–49 Nm).
• M20 plugs (e.g., many Subaru): roughly 29–33 lb-ft (39–45 Nm).
• Plastic pans/one-time-use plastic plugs: follow the exact factory spec and replacement interval; do not over-torque.
• Washers: replace crush/bonded washers every oil change unless the plug is designed with an integrated, reusable seal and the manufacturer says reuse is acceptable.

These ranges are guidelines, not a substitute for model-specific specs. Using the correct washer and torque is critical to avoid leaks and damaged threads.

Red flags and special cases to watch

Some designs need extra care; these notes can prevent expensive mistakes.

• Plastic oil pans and plastic drain plugs (common on newer European models) often require a new plug each service; the old one is single-use.
• Internal-hex or Torx plugs can round out if the wrong bit is used; fully seat the tool and apply steady torque.
• Aftermarket oversized “repair” plugs are for damaged pans; avoid unless you are repairing stripped threads.
• Do not mix thread pitches (e.g., forcing M14x1.25 into M14x1.5). If it doesn’t thread smoothly by hand, stop.
• Aluminum pans strip easily; always use a torque wrench and a fresh washer.
• If your manual lists an extraction method (no drain plug service), follow the factory procedure to avoid warranty issues.

If anything seems unusual—plastic plug, captive seal, odd head—pause and verify the exact part number and spec before proceeding.

Quick, real-world examples

These examples illustrate how specs commonly look when verified through OEM sources.

• 2015 Honda Civic 1.8L: M14x1.5 drain plug, 17mm head; 14mm crush washer; typical torque ~29 lb-ft (39 Nm).
• 2019 Subaru Outback 2.5L: M20x1.5 drain plug, 17mm head; 20mm crush washer; typical torque ~31 lb-ft (42 Nm).
• 2018 VW Golf 1.8T/2.0T with plastic pan: One-time-use plastic drain plug with O-ring; replace plug each change and torque per VW spec.

Your vehicle may differ; always confirm by VIN lookup or in the owner’s/service manual.

How to get your exact answer right now

If you want a definitive size without measuring, you can pull it from official parts data quickly.

• Enter your VIN on the automaker’s parts site or a trusted OEM catalog (e.g., Toyota, Honda, Subaru, VW, etc.).
• Navigate to the “Engine” → “Oil Pan/Drain Plug” diagram to find the plug and washer part numbers and specs.
• Buy the OEM plug/washer or use the specs to source an exact-match aftermarket part.

This method eliminates guesswork and ensures you have the correct thread, pitch, head style, and sealing washer.

Summary

There is no single oil drain plug size. Most cars use M12 or M14 metric plugs, some use larger M16/M20, and a few applications—especially older domestic or newer plastic pans—have unique requirements. The precise answer for your vehicle comes from the owner’s manual or a VIN-based OEM parts lookup, or by measuring the plug’s diameter and thread pitch with a caliper and thread gauge. Use the correct washer and torque to spec to avoid leaks and stripped threads.

What size bolt is the oil drain plug?

There is no universal bolt size for an oil drain plug; sizes vary by vehicle make, model, and year. You must determine the correct size for your specific car by checking its owner’s manual or looking up the part for your vehicle. Common sizes exist, such as M12, M14, M16, and M20, with corresponding thread pitches like 1.25, 1.5, or 1.75. 
How to Find the Correct Oil Drain Plug Size

1. Check the Owner’s Manual: This is the most reliable source for your vehicle’s specifications, including the correct thread size and type for the drain plug. 
2. Look Up Parts Online: Use a parts lookup tool for your vehicle’s make, model, and year to find the exact drain plug size you need. 
3. Inspect the Existing Plug: If the old drain plug is still in the vehicle, check for markings or measure it. However, be cautious as the wrong plug may fit but cause leaks or damage. 

Common Drain Plug Size Formats
Drain plug sizes are typically expressed in two parts: 

• Bolt Size: The diameter of the bolt, e.g., M12, M14, M16.
• Thread Pitch: The distance between the threads, e.g., x1.25, x1.5, x1.75.

For example, an M14x1.5 drain plug has a diameter of 14mm and a thread pitch of 1.5mm. 
Important Considerations

• Avoid Guessing: Using the wrong size can lead to oil leaks or a stripped oil pan, which is an expensive repair. 
• Check for a Gasket: The drain plug will require a gasket (often copper or aluminum) for a proper seal. 
• Soft Aluminum Plugs: Some recommend using a softer aluminum drain plug, as it’s more likely to damage its own threads before damaging the softer threads of the aluminum oil pan. 

What size socket do I need to remove a drain plug?

There is no universal drain plug socket size; the correct size depends on the vehicle’s make and model and is typically a metric socket in sizes like 14mm, 15mm, 17mm, or 19mm. To find the exact size for your car, check your owner’s manual, inspect the bolt head, or look for a general tool set that includes a range of metric sockets. 
How to determine the correct size:

1. Check the owner’s manual: The owner’s manual for your car will often list the bolt size needed to change the oil. 
2. Inspect the bolt head: Look at the existing oil drain plug to see its size. 
3. Use a general metric socket set: Common sizes are 14mm, 15mm, 17mm, and 19mm. A set that covers these common sizes is a good start. 
4. Consider a 6-point socket: A 6-point socket is recommended over a 12-point socket because it provides a better grip and is less likely to strip a pre-tightened or damaged drain plug. 

Important considerations:

• Metric vs. SAE: Most modern cars use metric sizes, but older cars or specific components may use SAE (standard) sizes. 
• Don’t overtighten: Always avoid overtightening or forcing the drain plug, as this can lead to damage. 
• Replace the gasket: Always replace the gasket on the drain plug, as it is crucial for preventing oil leaks. 

Are all oil drain bolts the same?

Different oil drain plugs and Gaskets are required for different vehicles. Drain plugs & gaskets vary from make, model, and even year. We recommend always checking your owners manual or any parts lookup like our Application Search to find the right drain plug.

How to find out oil drain plug size?

Measure Diameter
Measure the width of the plug at the widest part of the threads. If your plug measures 12mm you will need to start looking at plugs in the size range of “M12 x 1.25 to M12 x 1.75″. The “M12” refers to the diameter you measure from the widest part of the threads on your OEM sump plug.