What is the size of an oil plug?

There isn’t a single oil drain plug size—most passenger vehicles use metric threads such as M12×1.25, M12×1.5, M14×1.5, or M16×1.5, with hex-head sockets typically ranging from 13 mm to 19 mm; older U.S. models may use SAE threads like 1/2″-20 or 5/8″-18. The exact size depends on your vehicle’s make, model, engine, and oil pan design, so the only definitive answer comes from the owner’s manual, a dealer lookup by VIN, or direct measurement of the plug and washer.

Why there’s no single “standard” oil plug size

Automakers select drain plug sizes based on engine design, oil pan material (steel, aluminum, or composite/plastic), packaging constraints, and desired torque/sealing characteristics. Even within one brand, different engines and model years can use different plug and washer dimensions, and some newer vehicles use single-use plastic plugs in plastic pans. That’s why a universal size doesn’t exist—and why confirming your specific application is important.

The most common sizes you’ll encounter

The lists below summarize the thread sizes and socket/drive types most frequently found on light-duty vehicles. Use them as a starting point, but verify before buying parts.

• Common metric thread sizes: M12×1.25, M12×1.5, M14×1.25, M14×1.5, M16×1.5, and on some larger pans/trucks, M18×1.5 or M20×1.5.
• Common SAE/imperial thread sizes on older North American vehicles: 1/2″-20 UNF, 9/16″-18 UNF, 5/8″-18 UNF.

These thread sizes cover the vast majority of cars and light trucks. If yours is outside these ranges, it’s likely a specialty or heavy-duty application—double-check with the manufacturer.

Beyond thread size, the head or drive style determines the tool you’ll need. Here are the most typical head sizes and styles:

• Hex-head socket sizes: 13 mm, 14 mm, 15 mm, 17 mm, and 19 mm (larger plugs can be 21–24 mm).
• Internal hex (Allen): often 6 mm or 8 mm on some European applications.
• Torx: commonly T45 or T50 on certain aluminum/plastic pans and cartridge housings.
• Square-drive: some plugs accept a 3/8″ or 1/2″ ratchet directly.

Knowing both the thread and head/drive type ensures you get the right replacement plug and have the correct tool on hand for service.

Typical plug sizes by brand (general guidance)

The following brand-by-brand notes reflect common patterns, but exceptions are frequent. Always verify by manual, VIN, or measurement.

• Honda/Acura: Often M14×1.5 thread with a 17 mm hex head; uses a 14 mm ID aluminum crush washer.
• Toyota/Lexus/Scion: Frequently M12×1.25 (14 mm hex) with a 12 mm ID washer; many trucks/SUVs use M14×1.5. Note: some Toyota cartridge filter housings include a small 3/8″ square-drive drain plug.
• Nissan/Infiniti: Commonly M12×1.25 (14 mm hex) with a 12 mm washer.
• Hyundai/Kia: Frequently M14×1.5 (17 mm hex) with a 14 mm washer.
• Mazda: Commonly M14×1.5 (17 mm hex); some models use M12.
• Subaru: Many models use M16×1.5 (often 17 mm hex) with a 16 mm washer; some variants use larger plugs—confirm by VIN.
• Volkswagen/Audi: Many engines use M14×1.5 (19 mm hex) on metal pans; numerous late-models have plastic pans with single-use plastic drain plugs that quarter-turn out.
• BMW/MINI: Commonly M12×1.5 (17 mm hex) or 8 mm internal hex; new sealing ring required each service.
• Mercedes-Benz: Often M14×1.5 or 8 mm internal hex; replace the sealing ring each time.
• Ford/Lincoln: Modern applications typically M14×1.5 or M12×1.75 (15 mm hex common); some engines use plastic single-use plugs in plastic pans; older models may be 1/2″-20 UNF.
• GM/Chevrolet/GMC/Cadillac: Often M14×1.5 or M12×1.75 (15 mm hex is common); older applications may use SAE threads.
• Ram/Chrysler/Jeep/Dodge: Frequently M14×1.5 (13–15 mm hex) with replaceable crush washer; verify on Hemi and turbo engines.
• Motorcycles/ATVs: Typically M12×1.5 or M14×1.5 (12–17 mm hex); always check per model.

Because mid-cycle changes and engine-specific designs are common, treat these as typical—not definitive—pairings.

How to confirm your exact size quickly

Use the steps below to identify the correct drain plug and washer without guesswork.

1. Check the owner’s manual or service manual: many list the drain plug and washer size, part number, and torque spec.
2. Call a dealer with your VIN: parts departments can provide the exact plug and sealing washer dimensions or part numbers.
3. Measure the old plug: use a caliper to measure thread diameter (e.g., ~12 mm, ~14 mm) and a thread pitch gauge to confirm pitch (e.g., 1.25, 1.5). The socket size can be read from your tool.
4. Bring the plug to a parts store: most have thread gauges to match size and pitch and can supply the correct crush washer.
5. If the pan is plastic or aluminum, check for single-use plugs: some are designed to be replaced each service and have much lower torque specs.

Confirming size and reusability up front prevents cross-threading, leaks, and damage to the oil pan—especially on softer aluminum or composite pans.

Torque and sealing washer guidance

Correct torque and sealing are as critical as size. Keep the following in mind when reinstalling an oil plug.

• Typical torque ranges (always verify for your engine): M12 plugs ~20–25 lb-ft (27–34 N·m); M14 ~25–30 lb-ft (34–40 N·m); M16 ~30–35 lb-ft (40–47 N·m). Plastic pans/plugs can be far lower (often 7–14 lb-ft / 10–20 N·m).
• Use a new crush washer each service unless the plug has an integral captive gasket designed for reuse. Aluminum and copper are common materials; match the washer’s inner diameter to the thread size (e.g., 12 mm, 14 mm, 16 mm).
• Clean the sealing surface on the pan before installation, and lightly oil the threads of the plug/seal if specified by the manufacturer.
• Avoid overtightening—stripped threads and cracked pans are costly. A torque wrench is strongly recommended.

Proper torque and a fresh, correctly sized washer are the two best defenses against seepage and pan damage.

Special cases on newer vehicles

Some late-model designs deviate from traditional metal drain plugs; note the following trends.

• Plastic oil pans with single-use drain plugs: found across several brands; the plug and its O-ring are replaced at every oil change, and torque specs are low.
• Cartridge filter housings with small drain caps: separate from the pan plug, these often use Torx or a square-drive to drain the filter housing before removal.
• Aftermarket quick-drain valves (e.g., ball-valve types): available in most common thread sizes (e.g., M12×1.25, M14×1.5) and can simplify future services.
• Oversize/self-tapping repair plugs: used to salvage lightly damaged threads; however, a proper insert repair (e.g., helicoil) is preferred for longevity.

If your vehicle uses a nontraditional plug or housing, follow the manufacturer’s service procedure closely to avoid leaks or damage.

Summary

There is no universal oil drain plug size. Most passenger vehicles use metric threads—commonly M12×1.25, M12×1.5, M14×1.5, or M16×1.5—with hex heads in the 13–19 mm range, while some older North American models use SAE threads. The only reliable way to know your plug size is to consult the manual or dealer by VIN, or measure the existing plug, and always pair it with the correct crush washer and torque spec. This ensures a leak-free seal and prevents costly damage to the 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. 

What size is an oil plug?

There is no single standard size for an oil drain plug; the size varies by vehicle make and model. Common sizes can range from 10mm to 21mm for the wrench or socket, with common thread sizes being, for example, an M12x1.75 thread with a 15mm head. To find the correct size for your vehicle, check your owner’s manual, the product specifications, or use calipers to measure the plug’s threads yourself. 
Why there’s no universal size 

• Manufacturer Variations: Different car manufacturers use different designs for their oil pans and drain plugs, leading to variations in size.
• Component Specifics: The size isn’t universal because the oil pan, drain plug, and gasket all differ between vehicles.

How to find the correct size for your vehicle

1. Check the Manual: The most reliable way to find the correct size is to consult your vehicle’s owner’s manual or the product specifications. 
2. Measure the Plug: If you can’t find the information in the manual, you can use a ruler or digital calipers to measure the diameter of the plug’s threads to determine its size. 
3. Look for Markings: Some oil plugs have markings on their surface, such as “M12x1.5”, which can indicate the thread size. 
4. Use a Tool Kit: A socket set with a range of both SAE and metric sizes is a good investment, especially if you work on different vehicles. 

Are most oil drain plugs the same size?

There isn’t one size that fits all cars. Go to the autoparts place and tell them what car you have and they will look it up for you. If the threads on the oil pan hole are stripped out you can get an oversized drain plug to fit in. That is common and the plugs will rethread the hole as it is screwed in.

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.