What size socket for Subaru?
For wheel lug nuts on most Subaru models, you’ll typically need a 19mm socket; some models use 17mm or 21mm. Always verify by inspecting your lug nuts or consulting your owner's manual.
Understanding the question
Subaru maintenance tasks vary, and the socket size you need depends on the job (lug nuts, spark plugs, drain plugs) and the model/year. Below are the common sizes you’re likely to encounter and how to confirm them for your specific Subaru.
Common sizes by task
The following sections cover typical sizes used on Subaru vehicles and a quick method to verify the exact size for your model.
Wheel lug nuts
Most Subarus use a 19mm lug wrench/socket across flats for stock wheels. Certain trims with different wheels or aftermarket lug nuts can use 17mm or 21mm across flats. Always measure the lug nut across flats or check the owner's manual for your exact model.
- Common lug-nut size: 19mm across flats (most models)
- Alternative sizes you may encounter: 17mm or 21mm across flats (typically with aftermarket wheels or rare factory setups)
Verifying the exact size on the wheel hub or lug nuts is the best way to avoid rounding bolts during removal and to choose the correct socket.
Spark plugs
Spark plug sockets come in sizes that correspond to the plug hex. Subaru engines typically use a 5/8 inch (16mm) or 13/16 inch (20mm) spark plug hex. The safe approach is to check the plug's hex size (the width across the flats of the plug) and use the matching spark plug socket, usually with a rubber insert to hold the plug.
- Common spark plug socket hex sizes: 5/8" (16mm) or 13/16" (20mm)
- Note: Engine family (EJ, FA, FB, etc.) may determine the exact plug hex; verify from plug specification or service manual
Using the incorrect spark plug socket can strip the plug or drop it into the cylinder; confirm the hex size before purchase or use the original equipment plugs as reference.
Oil drain plugs and other bolts
Oil drain plugs are often 14mm hex on many Subaru engines, but bolt head sizes vary across engines and years. For other bolts encountered in maintenance, measure the head across flats or consult the service manual to avoid rounding off fasteners.
- Common oil drain plug hex: 14mm (varies by engine)
- Other bolt sizes differ by job and model; verify per engine
Confirming the exact size helps you apply the correct torque and prevent damage to fasteners.
How to verify quickly
If you are unsure, here are quick verification steps: check the owner's manual or the service manual for exact specs; measure the fastener head with a ruler or caliper; bring the fastener or nut to an auto parts store to match the size.
What if you have aftermarket wheels?
Aftermarket wheels may use different lug nut seat types or sizes; always verify. If uncertain, bring a sample nut or lug to a parts store for a precise fit.
Summary
In short, the most common lug-nut socket for Subaru is 19mm across flats, with occasional 17mm or 21mm cases. Spark plugs typically require a 5/8" (16mm) or 13/16" (20mm) spark plug socket depending on the engine, and oil drain plugs are often 14mm hex but can vary. Always confirm for your model/year to avoid damage and ensure proper torque.
What size socket for Subaru tires?
19mm
The most common socket size of Subaru lug nuts is 19mm (3/4”).
What size socket for Subaru lug nuts?
The correct socket size for most Subaru lug nuts is 19mm (3/4"). While most Subarus use this size, it's crucial to use a high-quality, thin-wall, 6-point socket designed for automotive use to avoid damaging the lug nuts or wheel.
Details to consider
- Standard size: The most common lug nut size is M12x1.25, which requires a 19mm socket.
- Avoid damage: Using an undersized socket can strip the nut, while an oversized one can cause it to slip. A 6-point socket is recommended over a 12-point socket to prevent rounding the corners.
- Specialty sockets: Some aftermarket lug nuts may have special shapes, like spline drives, which require a specific key socket.
- Older models: Some older Subaru models might require a different size, such as a 21mm socket for those with a 14mm lug nut, but this is rare.
- Protect your wheels: If you have alloy wheels, consider using a thin-wall impact socket or a socket with a protective sleeve to prevent scratching the finish.
Does Subaru use SAE or metric?
Subaru uses the metric system for its fasteners, including the most common lug nuts which are often M12x1.25mm. This is standard for Japanese-made cars, so you will need a set of metric tools, like a 19mm socket, to work on the lug nuts.
- Fasteners: Almost all bolts, nuts, and other fasteners on a Subaru are metric.
- Lug nuts: The most common lug nut size is M12x1.25mm. To remove them, you will need a 19mm socket.
- Tools: A metric socket set and metric wrenches are essential for any maintenance or repair.
- JIS vs. DIN: Subaru often uses Japanese Industrial Standard (JIS) bolts, which have some differences in head size and pitch compared to the more common DIN metric sizes.
What size socket for Subaru head bolts?
14mm x 12 pt
Socket size: 14mm x 12 pt. Use for Installation and removal of head bolts on Subaru flat boxer engines.
