What size lug nuts on a Subaru Outback?
If you’re replacing wheels or performing maintenance on a Subaru Outback, the lug nut size isn’t a single number you can rely on for every year. Specs vary by model year, trim, and wheel type. This article outlines the typical thread sizes you’ll encounter and how to confirm the exact specification for your vehicle.
Bolt pattern and thread size vary by year and wheel type
Most Subaru Outbacks use a 5x100 bolt pattern, but the lug nut thread size can differ between generations. The two most common metric thread sizes you’ll see are M12 x 1.25 and M12 x 1.5. Using the wrong lug nut size can damage threads or wheels, so it’s important to verify against your specific year and wheel setup.
- M12 x 1.25
- M12 x 1.5
Verifying the exact size for your Outback requires checking your model year and trim, consulting the official parts diagrams, or comparing with your current lug nuts. Once you know the correct thread size, you’ll also want to ensure you’re using the proper seat type and torque specification for safe operation.
How to confirm the exact size for your model
To determine the precise lug nut size for your Outback, use these steps. They help account for year-by-year variations and aftermarket wheel differences.
- Identify your exact model year and trim level, then consult the Subaru owner’s manual or official parts catalog for lug nut specifications.
- Inspect an existing lug nut or wheel stud to measure diameter and pitch with a caliper or thread gauge.
- Compare measurements to common sizes (M12 x 1.25 and M12 x 1.5) and confirm the lug nut seat type (most Subaru wheels use a conical/tapered seat, but verify for your wheels).
- If you have aftermarket wheels, verify with the wheel supplier or a qualified technician that the lug nuts match both the thread size and seat type.
- Tighten lug nuts to the manufacturer’s recommended torque, typically around 83 ft-lb (112 N·m) in a star pattern, and recheck after a short drive.
For any uncertainty, contact a Subaru dealership or a trusted tire shop to ensure you’re using the correct lug nuts for your specific Outback configuration.
Summary
In short, Subaru Outbacks commonly use M12 x 1.25 or M12 x 1.5 lug nut threads with a 5x100 bolt pattern, but exact specifications depend on the model year and wheel type. Always verify with your vehicle’s manual or parts diagrams, especially if you’re working with aftermarket wheels. After confirming the correct size, use the proper torque and seat type to keep wheels secure and safe.
Is 1/2 or 3/8 better for lug nuts?
Is 1/2 or 3/8 better for lug nuts? A 1/2-inch drive is better for lug nuts because it covers the torque range most vehicles require and allows you to tighten them with confidence.
Is a 13/16 socket the same as 21mm?
No, a 13/16 inch socket is not exactly the same as a 21mm socket, but they are very close and often considered interchangeable, as 13/16 inch is approximately $20.65$mm. Because of the small difference, one size may fit a nut or bolt more snugly than the other depending on manufacturing tolerances. The 13/16" socket often provides a tighter fit on many $21$mm lug nuts.
- 13/16" conversion: 13/1613 / 1613/16 inch is equal to approximately 20.6520.6520.65 mm.
- 21mm conversion: 212121 mm is equal to approximately 13/1613 / 1613/16 inch, or 0.8270.8270.827 inches.
- Practical application: While they are theoretically different, many tools and parts manufacturers list them as equivalent, making them effectively interchangeable in practice.
- Best fit: If you have both a 13/16" and a 21mm socket, it is best to try both to see which one fits the fastener most securely without being too loose or too tight. A tighter fit is generally preferred to avoid rounding the fastener head.
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.
What size lug nuts for a Subaru Outback?
The lug nut size for most Subaru Outbacks is 12mm x 1.25mm. The corresponding socket size is 19mm or 13/16 inch, and the typical torque specification is between 80 and 110 ft-lbs for alloy wheels.
Lug nut specifications
- Thread size: 12mm x 1.25mm (This is the standard for most recent Subaru models)
- Socket size: 19mm or 13/16 inch
- Torque specification: 80-110 ft-lbs for alloy wheels (always check your owner's manual for exact specs)
- Seat style: 60-degree conical (this is a common style for many Subaru factory wheels)
Important considerations
- Older models: Some older Outback models may have used a different size. Always confirm the size with your owner's manual or by checking the existing lug nuts.
- Aftermarket wheels: If you are using aftermarket wheels, the lug nut size and style might be different.
- Use the correct socket: It is crucial to use a properly fitting socket to avoid damaging the lug nuts. A 6-point socket is often recommended over a 12-point socket to prevent stripping the corners.
