What Size Bolt Is Used to Change Oil?

There isn’t one universal size. Most vehicles use an oil drain plug that takes a 13–19 mm socket, with 14 mm, 15 mm, and 17 mm being the most common; some domestic models use 5/8″ or 3/4″. A few European models use internal hex (Allen) 6–8 mm or Torx. The exact size depends on your vehicle’s make, model, and engine, so verify in the owner’s manual or by measuring before you start. Below is a concise guide to typical sizes, how to identify yours, and the tools and torque you’ll likely need.

What “size” means for the oil drain plug

When people ask about the “bolt size” for changing oil, they usually mean the socket size that fits the oil pan drain plug head. However, two measurements matter: the head size (the socket you use) and the thread size (diameter and pitch of the plug itself). Knowing both helps you select the right tool, torque spec, and crush washer.

Head size vs. thread size

The head size determines the socket or key you use to loosen the plug (for example, 17 mm hex or 6 mm internal hex). The thread size (for example, M14 x 1.5) is what you’d need if replacing the plug or washer. Head size is not a reliable indicator of thread size—always verify.

Common oil drain plug sizes by type

The following list summarizes the socket or key sizes you’re most likely to encounter across passenger vehicles and light trucks. Use this as a starting point, not a substitute for checking your specific vehicle.

• Metric hex-head sockets: 13 mm, 14 mm, 15 mm, 17 mm, 19 mm
• SAE hex-head sockets: 5/8″ (≈15.9 mm), 3/4″ (≈19.0 mm)
• Internal hex (Allen): 6 mm, 8 mm
• Torx/internal drive (less common on drain plugs): T45, T50

These cover the vast majority of modern cars. If your plug doesn’t match, it may be aftermarket, damaged, or an unconventional design—double-check before applying force.

Typical sizes by brand (guidance, not guarantees)

This brand-oriented overview reflects frequent patterns seen in service, but manufacturers vary by engine and model year. Always confirm with your VIN, owner’s manual, or parts catalog.

• Toyota/Lexus: Often 14 mm hex head; many use M12 x 1.25 threads
• Honda/Acura: Often 17 mm hex head; many use M14 x 1.5 threads
• Nissan/Infiniti: Frequently 14 mm hex head; threads vary (M12 x 1.25 or M14 x 1.5)
• Mazda: Commonly 14 mm hex head; threads vary by engine
• Hyundai/Kia: Often 17 mm hex head; many use M14 x 1.5 threads
• Subaru: Often 17 mm hex head; many models use larger threads (for example M16 x 1.5)
• Ford: Commonly 13 mm or 15 mm hex head; some models use plastic quick-drain plugs
• GM/Chevrolet/GMC: Frequently 15 mm hex head; many use M14 x 1.5 threads
• Volkswagen/Audi: Often 19 mm hex head or 6–8 mm internal hex; verify per engine
• BMW/MINI: Often 17 mm hex head or 8 mm internal hex; torque is critical on aluminum pans
• Mercedes-Benz: Mix of 13 mm hex and internal hex/Torx depending on engine
• Motorcycles (general): 12–17 mm hex heads are common; threads often M12 x 1.25 or M14 x 1.5

Use these notes to narrow your tool choice before crawling under the vehicle. A quick check against the manual or a parts lookup using the VIN will confirm the exact spec.

How to identify your exact drain plug size

If your manual doesn’t clearly list it, these steps will help you identify the correct size safely and accurately.

1. Test-fit sockets on the plug head until one fits snugly without play (do not force it).
2. If it’s an internal drive, test a 6 mm and 8 mm Allen key; for Torx, start with T45/T50.
3. Measure thread diameter with calipers if the plug is out (common: M12, M14, M16).
4. Check thread pitch with a gauge or match to a replacement plug/washers labeled with pitch (e.g., 1.25, 1.5).
5. Look up the OEM part number by VIN in a dealer or reputable online catalog (this also reveals the washer size).

Proper identification prevents rounded heads, stripped pans, and leaks—and ensures you have the correct crush washer and torque value.

Typical torque specs and crush washers

Over-tightening is a leading cause of damaged oil pans. Use a torque wrench and a new crush washer every oil change unless your OEM specifies reusable sealing.

• M12 drain plug: about 25–30 ft-lb (34–40 Nm) unless the OEM specifies otherwise
• M14 drain plug: about 30–35 ft-lb (40–48 Nm) unless specified otherwise
• M16 drain plug: about 35–40 ft-lb (47–54 Nm) unless specified otherwise
• Aluminum pans and plastic drain plugs: often lower—commonly 18–25 ft-lb (24–34 Nm). Always follow the OEM spec.
• Crush washers: typically single-use aluminum or copper; inside diameter matches the plug thread (e.g., 12 mm, 14 mm, 16 mm)

Because torque varies by pan material and plug design, check your service manual. If you don’t have a spec, err on the lower end and confirm no seepage after warm-up.

Tools you’ll likely need

Having the right tools ready makes the job cleaner, safer, and less prone to damage.

• Socket set: 13–19 mm (and 5/8″, 3/4″ if you work on domestic models)
• Allen keys: 6 mm and 8 mm; Torx bits T45/T50 for certain European models
• Torque wrench covering roughly 15–50 ft-lb (20–70 Nm)
• New crush washer matched to your plug size
• Drain pan, gloves, rags, and brake cleaner for cleanup

Lay out tools before you start; confirming fitment up front helps avoid rounded fasteners and spills.

Notable exceptions and special cases

Some vehicles use nonstandard designs or parts that change the tools required—and the tightening procedure.

• Quick-drain valves (aftermarket Fumoto or OEM plastic plugs) use unique methods and torque—follow their instructions.
• Cartridge oil filter caps often require large sockets (commonly 27, 30, 32, or 36 mm), separate from the drain plug.
• Topside oil extraction systems (some European models) reduce plug use but you still need the correct size for periodic inspections.

If your setup doesn’t match a conventional metal hex plug, stop and consult the factory procedure to avoid breakage or leaks.

Bottom line

There is no single “oil change bolt” size. Expect to use a 13–19 mm socket (14, 15, or 17 mm most often), or 5/8″–3/4″ on some domestic models, with occasional 6–8 mm Allen or Torx on European engines. Confirm your vehicle’s exact spec via the manual or a VIN-based parts lookup, use the correct crush washer, and tighten to the OEM torque.

Summary

Most oil drain plugs take a 13–19 mm socket; 14, 15, and 17 mm are the most common, with 5/8″ and 3/4″ seen on some domestic vehicles and 6–8 mm internal hex or Torx on select European models. Thread sizes frequently include M12 x 1.25, M14 x 1.5, and M16 x 1.5, but you must verify for your engine. Use a new crush washer and torque to spec—typically 25–40 ft-lb depending on size and pan material—to avoid leaks and damage.

What size socket is an oil pan bolt?

There is no universal oil pan socket size; the specific size depends on the vehicle’s year, make, and model, but common sizes include 15mm, 16mm, or 9/16-inch. To find the correct socket, you’ll need to check your vehicle’s manual or visually inspect the drain plug itself, as a proper fit is crucial to avoid rounding the bolt head. 
How to find the right socket size:

1. Check your vehicle’s manual: or a reliable parts website for your specific car. 
2. Visually inspect the drain plug: before you start your oil change. The size of the wrench needed corresponds to the width across the bolt’s flats. 
3. Have a basic metric socket set: on hand, as common sizes range from 10mm to 21mm, with 15mm being a frequent choice. 

Tips for success:

• Use the correct size: A socket that is too small can damage the bolt head, while one that is too large can also cause issues and damage. 
• Use a 6-point socket: This type provides a more secure fit on the bolt head, reducing the risk of stripping. 
• Clean the bolt and pan: Ensure the bolt and surrounding area are clean before reinstalling to maintain a proper seal and prevent future leaks. 
• Consider writing it down: For future reference, note the drain plug size under the hood of your car. 

What size is the oil change bolt?

There isn’t a single “oil change bolt size” because sizes vary by vehicle. To find the correct size for your car, you must identify the specific drain plug bolt head size for your vehicle’s make and model. You can typically use a socket wrench set with common metric sizes like 14mm, 15mm, 17mm, or 19mm. If you don’t know the size, you can buy a vehicle-specific part or use a tool to measure the bolt, such as digital calipers, but a wrench that is too small can strip the head. 
How to Find the Right Size

1. Check Your Vehicle’s Owner’s Manual: Opens in new tabYour manual will often have the specific size of the drain plug. 
2. Consult an Auto Parts Store: Opens in new tabTell the store your vehicle’s year, make, and model, and they can look up the correct size. 
3. Measure the Bolt: Opens in new tabIf you have calipers or a ruler, you can measure the width of the bolt head to determine its diameter. 
4. Test Common Socket Sizes: Opens in new tabIf you don’t know the size, you may have to try the common metric socket sizes in the 14mm to 19mm range. 

Important Tips

• Use the Correct Tool: Use a socket or wrench that fits the bolt head snugly to avoid stripping it. 
• Replace the Washer: Always use a new crush washer when reinstalling the drain plug to prevent leaks. 
• Use a Proper Socket: For best results, use a 6-point socket, as these provide a more secure grip than 12-point sockets and reduce the risk of stripping. 

What size socket is needed for an oil change?

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. 

What size tool do I need to change oil?

Ratchet and Socket Set
Get a set that includes some metric and SAE sizes, and if you’re starting out, a 3/8” drive should do just fine. Ratchets and sockets also come in 1/4, 1/2″, 3/4″, and 1” drives. Many medium sized kits will include ratchets and sockets in 3/8” and 1/2″ drive.