What size wrench do I need for an oil plug?

Most oil drain plugs use a metric hex head between 13 mm and 17 mm (commonly 14 mm or 15 mm), while some trucks/SUVs go up to 19 mm; a minority use an internal hex (6 mm or 8 mm) or, less often, Torx. Always verify your vehicle’s spec and use a 6‑point socket to avoid rounding. Below is a breakdown to help you pick the right tool and avoid common mistakes.

Why there isn’t a single wrench size

Oil drain plug dimensions vary by manufacturer, engine family, and even model year. Automakers choose different plug heads and thread sizes to match the oil pan material (steel vs. aluminum), space constraints, and sealing method (crush washer vs. reusable gasket). Aftermarket magnetic plugs can alter head size, too. That’s why the “right” wrench is best confirmed by your owner’s manual, service data, or a quick measurement—though certain sizes are especially common.

Common drain plug sizes by make and vehicle type

The following list summarizes frequently seen oil drain plug head sizes across popular brands and vehicle categories. Use it as a starting point; confirm for your exact engine.

• Toyota, Honda, Nissan: Typically 14 mm hex; some use 17 mm depending on engine.
• Mazda, Subaru: Often 14 mm or 17 mm hex.
• Hyundai, Kia: Commonly 17 mm hex; some models 14 mm or 19 mm.
• Ford (cars/crossovers): Frequently 13 mm or 15 mm hex; select models use replaceable plastic drain plugs or unique designs—check the manual.
• GM/Chevrolet/GMC: 15 mm hex is common; some engines vary.
• Chrysler/Dodge/Jeep/Ram: Often 13 mm or 15 mm hex; larger trucks may be 15–19 mm.
• Volkswagen/Audi: Commonly 19 mm hex or internal hex (Allen) 6 mm/8 mm on some engines.
• BMW, MINI: Frequently 17 mm hex or internal hex (Allen) 8 mm depending on engine generation.
• Mercedes‑Benz: Typically 13 mm hex or internal hex (Allen) 8 mm; some engines route oil changes through the filter housing—check procedure.
• Volvo: Often 17 mm hex; some models use internal hex or specific drain designs—verify per engine.
• Motorcycles: Commonly 12 mm, 14 mm, or 17 mm hex; consult the service manual for torque and washer type.
• Older U.S. vehicles (SAE): Occasionally 1/2″, 9/16″, or 5/8″, though most modern vehicles are metric.

These patterns cover a large share of vehicles, but exceptions exist. If your plug doesn’t match, you may be dealing with an internal hex, a Torx-style plug, or an aftermarket replacement with a different head.

How to identify the correct size quickly

When you’re unsure, these steps help you pick the correct wrench or socket without guesswork and reduce the chance of rounding the plug.

1. Check the owner’s manual or official service information for the drain plug spec and torque.
2. Confirm the plug type: external hex, internal hex (Allen), Torx, or a manufacturer-specific plastic/quick-release design.
3. Clean the plug head and test-fit a 6‑point socket—start with 14 mm and 15 mm for cars, 17–19 mm for larger vehicles; it should fit snugly with no play.
4. If needed, measure across the flats with calipers or a wrench gauge to confirm size.
5. For internal hex, insert the Allen key/bit (often 6 mm or 8 mm) and check for a tight, full-depth engagement.
6. If your vehicle uses a replaceable plastic drain plug or twist-lock, obtain the specified tool and a new plug before starting.
7. Have a new crush washer or gasket on hand if your plug requires one; many do.

Spending a minute to verify size and plug style prevents stripped heads, damaged pans, and messy do-overs.

Tools and best practices

Using the right tools and technique protects the plug and the oil pan, especially aluminum pans that are easy to damage.

• 6‑point metric socket set (commonly 13, 14, 15, 17, 19 mm) with a 3/8″ drive ratchet; add 6 mm and 8 mm Allen bits for internal hex plugs.
• A torque wrench to tighten to spec; many passenger cars fall around 25–35 N·m (18–26 lb‑ft), while some trucks/large plugs run higher—always follow the manual.
• New crush washer or sealing gasket as specified (aluminum, copper, or fiber).
• Drain pan, gloves, rags, and brake cleaner to remove residue.
• A short extension and low-profile socket for tight clearances; avoid adjustable wrenches on stubborn plugs.

A 6‑point socket and proper torque are the best defense against rounded heads and stripped threads. Replace the washer each oil change if specified.

Quick reference: typical sizes and torque ranges

Use this at-a-glance guide to prepare your tool kit; verify exact torque and size for your engine.

• Most cars: 14 mm or 15 mm hex; torque often 25–35 N·m (18–26 lb‑ft).
• Japanese brands: Frequently 14 mm; torque commonly 29–39 N·m (21–29 lb‑ft), model-dependent.
• European brands: 17–19 mm hex or 6/8 mm internal hex; torque often 25–40 N·m (18–30 lb‑ft).
• Trucks/SUVs: 15–19 mm hex; torque can range 30–50 N·m (22–37 lb‑ft) depending on plug size and pan material.
• Motorcycles: 12–17 mm hex; torque varies widely—check the service manual.

Treat these as common ranges, not absolutes; relying on the official torque spec is essential to avoid leaks or thread damage.

Bottom line

You’ll most likely need a 14 mm, 15 mm, or 17 mm 6‑point socket for a passenger car oil drain plug, with trucks often requiring up to 19 mm. Some vehicles use 6 mm or 8 mm internal hex plugs, and a few use other specialized designs. Verify your exact size and torque in the manual, use a fresh washer if required, and tighten with a torque wrench to finish the job cleanly and safely.

Summary

Common oil plug wrench sizes are 13–17 mm for cars (with 14 mm and 15 mm leading), and up to 19 mm for larger vehicles; internal 6 mm/8 mm hex plugs also appear on some models. Confirm the spec for your engine, use a 6‑point socket and torque wrench, and replace the crush washer as needed to prevent leaks and damage.

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. 

What size socket do you need for 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.

What size is a standard oil drain plug?

There is no single “standard size” for an oil drain plug, as sizes vary by vehicle make and model. To find the correct size, you need to check your vehicle’s owner’s manual or measure your existing plug’s thread diameter (e.g., M12, M14) and the required wrench size for the head (e.g., 15mm, 17mm).
 
How to Determine Your Drain Plug Size

1. Check Your Owner’s Manual: This is the best first step to find the correct size specified for your vehicle. 
2. Measure Your Existing Plug:
   • Thread Diameter: Measure the widest part of the plug’s threads to get the metric (M) or standard (SAE) diameter (e.g., M12 means a 12mm thread diameter). 
   • Head Size: The head size (e.g., 17mm) is the measurement needed for the wrench or socket you’ll use to remove and install the plug. 
3. Use a Vehicle-Specific Parts Catalog: Websites for auto parts stores or manufacturers like Dorman Products and NAPA Auto Parts have tools to help you find the right drain plug by entering your vehicle’s year, make, and model. 

Common Size Examples
While not standard, here are some examples of common sizes: 

• Metric: M12 x 1.5, M12 x 1.75, M14 x 1.50.
• SAE (Imperial): 1/2-20.

What size wrench for oil plug?

What size wrench to use for an oil drain plug depends on the size of the oil drain plug itself, which is a long bolt head. There is no universal oil plug size, but they do come in just a few several standard sizes, such as ¼ inch (. 6 centimeters), 3/8 inch (. 9 centimeters), ½ inch (1.3 centimeters), etc.