What size socket is the oil drain bolt?

It depends on the vehicle: most passenger cars use a 13–19 mm hex socket for the oil drain plug, with 14 mm (common on Toyota/Nissan) and 17 mm (common on Honda/Subaru) the most frequent; many U.S. makes use 15 mm. Larger trucks/SUVs may need 19–21 mm. Some European models and motorcycles use Torx (T45–T50) or internal-hex/Allen (6–8 mm) instead. Always confirm in the owner’s/service manual or by checking the plug directly.

Why there isn’t one standard size

Automakers choose different drain plug thread sizes, materials, and head designs to suit engine and oil pan design, which changes the socket size needed. The socket size refers to the bolt head (or recess), not the thread diameter. Even within a brand, different engines and model years can vary, and some newer pans use plastic, twist-lock, or cartridge-style drain plugs that don’t take a conventional socket at all.

Quick reference by brand (common, not universal)

The following list summarizes typical oil drain plug head sizes seen in the field. Use it as a starting point, but verify for your exact year/engine.

• Toyota/Lexus: Often 14 mm hex
• Honda/Acura: Often 17 mm hex
• Nissan/Infiniti: Often 14 mm hex
• Subaru: Often 17 mm hex
• Mazda: Often 17 mm hex (some models 14 mm)
• Hyundai/Kia: Often 17 mm hex
• Volkswagen/Audi: Often 19 mm hex; some use T45–T50 Torx or 6 mm internal-hex on certain pans
• BMW/MINI: Many older models 17 mm hex; some newer use 8 mm internal-hex or T50 Torx (plastic plugs)
• Mercedes-Benz: Often 13 mm hex; some use 8 mm internal-hex
• Ford (cars/trucks): Frequently 15 mm hex; some 13 mm; certain modern plastic drain plugs are twist-lock (no socket)
• GM/Chevrolet/GMC/Cadillac: Frequently 15 mm hex; some 13 mm
• Chrysler/Dodge/Jeep/Ram: Commonly 13 mm or 15 mm; some trucks larger
• Motorcycles: Commonly 12–14 mm hex; some 17 mm; a few use internal-hex

These patterns cover a large share of vehicles, but exceptions are common—particularly on turbocharged or diesel engines, performance models, and vehicles with plastic composite oil pans.

How to identify your socket size in minutes

If you don’t have the manual handy, you can quickly determine the right tool without rounding the plug.

1. Clean the plug head so the tool seats fully.
2. Start with snug-fitting metric sockets: test 14, 15, 17, and 19 mm in that order; avoid loose fits.
3. If none fit, try Torx bits (T45–T50) or internal-hex/Allen (6 or 8 mm) to see if the plug has a recessed drive.
4. If it’s a plastic plug with tabs or a twist collar, consult the service procedure—many are removed by hand or with a small pry/turn tool, not a socket.
5. When in doubt, check the owner’s manual, factory service manual, or an OEM parts site for your VIN/engine.

A proper, snug fit is essential—using an undersized or sloppy socket can round the plug and turn a quick oil change into a repair.

Tools you’ll likely need

Having the right basics on hand makes the job safer and reduces the risk of damage.

• Metric sockets: 13, 14, 15, 17, 19 mm (and sometimes 21 mm for larger trucks)
• Bits: T45–T50 Torx; 6 mm and 8 mm internal-hex/Allen
• 3/8-inch drive ratchet (and breaker bar if needed), plus extensions
• Torque wrench capable of 20–50 ft-lb (27–68 N·m)
• New crush washer or sealing ring (copper, aluminum, or fiber as specified)
• Drain pan, gloves, rags, and eye protection

This compact kit covers nearly all modern vehicles and helps ensure the plug is tightened to specification without leaks.

Typical torque and washer notes

Oil drain plugs are designed to seal with modest torque and a fresh washer. Over-tightening can strip threads—especially on aluminum or plastic pans.

Common torque ranges (always verify for your engine)

Use these as general guides when the exact spec isn’t immediately available.

• M12 drain plug: typically 25–30 ft-lb (34–40 N·m)
• M14 drain plug: typically 30–35 ft-lb (40–47 N·m)
• M16 drain plug: typically 35–40 ft-lb (47–54 N·m)
• Plastic drain plugs: follow the service manual—often much lower torque or twist-lock with no torque spec

Replace the crush washer every oil change unless the manufacturer specifies a reusable seal. A new washer is often the difference between a clean, dry pan and a slow drip.

When the plug isn’t a standard hex bolt

Some vehicles use alternative designs that need different tools or procedures.

• Internal-hex (Allen): Common sizes are 6 mm and 8 mm.
• Torx: Often T45 or T50 on certain European and newer plastic plug designs.
• Square drive recess: Some plugs accept a 3/8-inch or 1/2-inch ratchet square directly.
• Plastic/twist-lock plugs: Found on some modern Ford and European engines; they release with a twist or tab—no socket.
• Aftermarket valves (e.g., Fumoto/quick-drain): May require a wrench once for installation; thereafter no socket is needed to drain.

Knowing which system you have prevents damage to plastic components and ensures a proper seal when reinstalled.

Bottom line

There isn’t a universal oil drain plug socket size. For most cars, expect 14, 15, or 17 mm; for larger or European models, be prepared for 19–21 mm, Torx, or internal-hex. Verify for your exact make, model, year, and engine, use a snug-fitting tool, replace the crush washer, and torque to spec to avoid leaks or damaged threads.

Summary

Most oil drain plugs take a 13–19 mm socket, with 14 mm, 15 mm, and 17 mm the most common across mainstream brands; some vehicles use 19–21 mm, Torx, or internal-hex designs. Because sizes vary by make, model, engine, and even oil pan material, confirm with the manual or by test-fitting the correct tool, and always use proper torque and a fresh washer for a reliable seal.

What socket size do I need for an oil change?

You need a socket wrench (14mm or 15mm), an oil filter wrench, an oil drain pan, a funnel, and a new oil filter.

What size is the bolt for the oil pan?

There is no universal size for an oil pan bolt; the correct size depends on the specific make and model of your vehicle, which can be a metric size (like M8, M12) or an imperial size (like 1/4-inch or 5/16-inch). To find the right size, you must consult your car’s owner’s manual or a vehicle-specific repair guide, or if replacing a bolt, use a proper-sized wrench or socket to remove the old one and match its specifications.
 
How to Determine the Correct Bolt Size

1. Check Your Vehicle’s Owner’s Manual: This is the most reliable way to find the exact bolt size and thread specification for your car. 
2. Use a Vehicle-Specific Repair Guide: Online resources or a printed manual for your car’s make and model will provide detailed specifications for all components. 
3. Examine the Old Bolt:
   • Metric Bolts: These will be labeled with an “M” followed by a number (e.g., M8, M12), with the number indicating the diameter. 
   • Imperial (SAE) Bolts: These will be specified with a fraction (e.g., 1/4-inch, 5/16-inch) indicating the diameter. 
4. Match the Wrench Size: If you can’t find the exact size, use a wrench that fits the bolt head snugly. A 15mm, 16mm, or 9/16-inch is common for some vehicles. 

Common Bolt Types and What They Mean

• Bolt Head Size: The size of the wrench needed to turn the bolt (e.g., 3/8 inch). 
• Thread Size: The diameter and pitch of the threads on the bolt. For example, a 5/16-18 bolt has a 5/16-inch diameter and 18 threads per inch. 
• M8 x 1.25 x 25: A common way to describe metric bolts. The “M” indicates it’s metric, “8” is the diameter in millimeters, “1.25” is the thread pitch, and “25” is the length in millimeters. 

Important Considerations

• Bolt Length: Opens in new tabNot all holes are the same depth, so always check the depth of the bolt holes to ensure you use the correct bolt length for each one. 
• Gaskets: Opens in new tabThe oil pan often uses a gasket to prevent leaks. Using the correct size bolt with the proper gasket is essential. 

What tool should you use to loosen the oil pan drain plug?

Play. So let’s go ahead open it up really quick. Yeah we’re going to use some tin snips why. Not cuts right through. There. And there we go just a little flexible dongle deal thingy.

What size socket is an oil drain plug?

The socket size for an oil drain plug varies depending on the vehicle’s make and model, but common metric sizes include 14mm and 17mm, with other possibilities ranging from 10mm to 21mm. There isn’t a single standard size, so you should determine the correct size for your specific vehicle before changing the oil to avoid stripping the plug. 
How to find the right socket size

1. Check your owner’s manual: The owner’s manual for your car will often list the correct socket size for the oil drain plug. 
2. Inspect the plug: Visually inspect the oil drain plug to see if you can determine the size. 
3. Look for common sizes: If your vehicle is a Japanese or European model, common metric sizes are 10mm, 12mm, 14mm, 15mm, 17mm, 19mm, and 21mm. 
4. Use a tool set: Purchase a good quality tool set that includes both SAE and metric sockets, or a set with a wide range of metric sizes. 

What to do if the socket doesn’t fit

• Do not force it: If a socket doesn’t fit the plug, do not try to force it, as you could strip the bolt. 
• Get the right size: Obtain the correct size for your vehicle. 
• Use a 6-point socket: A 6-point socket is often recommended because it provides better grip on the bolt head, reducing the risk of stripping the plug.