What size socket set do you need for car maintenance?

For most car maintenance, choose a metric-focused socket set with 1/4-inch, 3/8-inch, and 1/2-inch drives; 6-point shallow and deep sockets from 8–19 mm plus 21–22 mm; common lug-nut sockets (17, 19, 21 mm); spark plug sockets (5/8 inch/16 mm and 13/16 inch/21 mm, with a 14 mm thin-wall for some modern engines); a few extensions; a universal joint; a breaker bar; and at least one torque wrench. This coverage handles routine jobs from oil changes and brakes to wheels and many engine-bay fasteners.

Why choosing the right socket sizes matters

Automakers today overwhelmingly use metric fasteners, and the right mix of drive sizes, socket sizes, and accessories prevents rounded bolts, speeds up repairs, and keeps you within safe torque specs. The goal is broad coverage without buying redundant pieces you’ll rarely use.

The core kit most DIYers need

The items below form a balanced foundation that covers the vast majority of passenger-car service tasks without overbuying.

• Drive sizes and ratchets: 1/4-inch (light interior/trim work), 3/8-inch (general use), and 1/2-inch (wheels, suspension, higher torque).
• Metric 6-point sockets (shallow and deep): 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 mm. Add 21 and 22 mm for larger fasteners.
• Lug nuts: 17, 19, and 21 mm are most common; keep thin-wall versions if your wheels are tight on clearance.
• Spark plug sockets: 5/8 inch (16 mm) and 13/16 inch (21 mm); some modern engines need a 14 mm thin-wall, 12-point socket.
• Extensions: a mix such as 3-inch, 6-inch, and 10-inch in 1/4-inch and 3/8-inch; plus a universal joint (wobble) for awkward angles.
• Breaker bar: 1/2-inch drive for stuck fasteners and lug nuts.
• Torque wrenches: 3/8-inch (roughly 10–80 ft-lb) for engine/brake fasteners; 1/2-inch (roughly 30–150+ ft-lb) for wheels and suspension.

Together, these pieces cover oil changes, battery and accessory work, brake jobs, wheel service, and many underbody and engine-bay tasks on modern vehicles.

Useful add-ons by job

Depending on your vehicle and the work you plan to do, these extras can save time and prevent fastener damage.

• Bit sockets: Torx (T20–T55), internal/external Torx (E6–E14), and metric hex/Allen (4–10 mm) for brakes, interior, and engine covers.
• Triple-square/XZN: M8–M14 for many European makes (VAG/Audi/VW, BMW) on axles, head bolts, and drivetrain components.
• Impact sockets: 1/2-inch drive, 17–22 mm for use with impact wrenches; use only impact-rated sockets on power tools.
• Oxygen sensor socket: 22 mm (7/8 inch) slotted style for sensor removal without wire damage.
• Oil filter tools: model-specific cap sockets for cartridge filters; band or claw types for spin-on filters.
• Axle/hub nuts: large 30–36 mm sockets for some front axles (check your service manual).
• Line/crowfoot wrenches: useful on brake and power-steering lines where sockets won’t fit.

These add-ons target specific assemblies—especially on European brands and performance models—reducing the risk of stripping specialized fasteners.

Metric vs. SAE and regional notes

Most modern vehicles use metric hardware, but there are exceptions and regional trends that can influence what you buy.

• Modern cars (global): predominantly metric; focus on 8–19 mm plus 21–22 mm.
• Older U.S. vehicles and some aftermarket parts: may use SAE; a small SAE set (1/4–1 inch) can be handy for classics.
• Japanese/Korean brands: heavy use of 10, 12, 14 mm; often Torx and hex bits on interior/trim.
• European brands: frequent Torx, E-Torx, and triple-square (XZN) usage; plan for bit-socket coverage.
• Trucks/SUVs: larger fasteners common (21–24 mm); torque values are higher.
• EVs: fastener sizes are similar to ICE cars; expect more Torx/trim fasteners and delicate plastic clips.

Knowing your vehicle’s origin and era helps you prioritize metric versus SAE and guides which specialty bits to include.

6-point vs. 12-point and material choices

Socket design and alloy affect durability, grip, and safety—especially under high loads.

• 6-point sockets: stronger engagement, less rounding, ideal for stubborn fasteners; prefer as your default.
• 12-point sockets: useful in tight spaces and necessary for 12-point fasteners (e.g., some spark plugs).
• Materials: chrome-vanadium (Cr-V) for hand tools; chrome-molybdenum (Cr-Mo) for impact sockets.
• Finish: polished chrome for corrosion resistance and easy cleaning; black phosphate on impact sockets.
• Deep vs. shallow: deep sockets clear studs and nuts; shallow sockets fit where space is limited—own both in common sizes.

Choosing 6-point, quality alloys, and appropriate finishes ensures safer, longer-lasting tools and fewer rounded fasteners.

Buying tips and set size

Balanced sets avoid filler pieces while covering real-world needs. Consider the following when comparing kits.

• Piece count: 60–120 pieces is a practical range for DIY car work without bloating the kit.
• No skipped sizes: ensure complete runs (8–19 mm) in both shallow and deep sockets.
• Balance of drives: all three drives (1/4, 3/8, 1/2 inch) with matching extensions and adapters.
• Bit socket inclusion: Torx and hex bits add significant capability without large cost.
• Storage: sturdy, organized case or rails that keep sizes readable and accessible.
• Warranty and calibration: lifetime for hand sockets/ratchets; torque wrenches should be calibratable or replaceable.

A well-curated set minimizes trips to the store mid-job and avoids paying for dozens of seldom-used micro bits.

Example loadouts by budget

Here are practical combinations that reflect common maintenance needs, scaled by budget and ambition.

• Basic: 3/8-inch drive ratchet; shallow sockets 8–19 mm; deep sockets 10–19 mm; 17/19/21 mm lug sockets; 5/8 inch spark plug socket; 3- and 6-inch extensions; 1/2-inch breaker bar; 1/2-inch-to-3/8-inch adapter.
• Intermediate: Adds 1/4-inch and 1/2-inch ratchets; full shallow/deep 8–22 mm; Torx T20–T55 and hex 4–10 mm bit sockets; universal joint; 13/16 inch and 14 mm thin-wall spark plug sockets; 3/8-inch torque wrench; thin-wall lug sockets.
• Advanced: Adds E-Torx E6–E14; triple-square M8–M14; impact socket set 17–22 mm; oxygen-sensor socket; oil filter cap sockets; 1/2-inch torque wrench; longer extensions and wobble extensions; large axle nut socket (as specified by vehicle).

Scaling up in stages lets you match tools to the jobs you actually perform, keeping costs sensible while expanding capability.

Quick checklist

Use this at the store or online to confirm you’ve got the essentials covered.

• Drives: 1/4, 3/8, 1/2 inch ratchets and matching extensions.
• Sockets: 6-point metric 8–19 mm (plus 21–22 mm), shallow and deep.
• Lug: 17, 19, 21 mm (thin-wall preferred).
• Spark plug: 5/8 inch, 13/16 inch, and 14 mm thin-wall if needed.
• Accessories: universal joint, breaker bar, torque wrench(es).
• Bits: Torx, hex; add E-Torx and XZN if European.

If your cart matches this checklist, you’re set for most routine automotive tasks.

Summary

For car maintenance, prioritize a metric-heavy, 6-point socket set spanning 8–19 mm with 21–22 mm, supported by 1/4-, 3/8-, and 1/2-inch drives, deep and shallow sockets, lug and spark plug coverage, and the right accessories—extensions, a universal joint, a breaker bar, and torque wrenches. Add Torx/hex (and E-Torx/XZN for European cars) to extend capability. This mix balances cost, coverage, and safety for the majority of DIY automotive work.

What sockets do I need to work on a car?

Common socket sizes range from 8mm to 17mm. ½” drive sockets range from around 11mm to 36mm. These are sockets that can take the torque! Whether it’s tightening cylinder head bolts, or wheel bolts, these are the sockets you’ll need.

What size socket is best for working on cars?

If you are going to do a lot of work on automotive engines, you will need both a 3/8” and a 1/2” drive set. A 1/4” drive socket set is normally used on more delicate and smaller fasteners. If possible, I would try to locate a set that has 6-point sockets, not the more common 12-point sockets.

What size ratchet for car maintenance?

1/2 inch – 1/2″ sockets are generally used for nuts and bolts from around 10mm and up. A 1/2″ drive socket can apply enough force to undo all nuts on a car. There are also 3/4″ and 1″ ratchets but these are used on trucks, tanks and industrial machinery.

How big socket set do you need to change oil in a car?

Place a 3/8-inch (0.9 centimeters) socket in the socket wrench, fit it over the drain plug’s nut and turn it counterclockwise. The oil drain plug should open easily, draining the used oil from the engine. Make sure to place a bucket and some newspaper under the car’s engine to catch all the draining oil.