Metric vs SAE Tools: Which Does My Car Need?

Updated March 2026 · 55 vehicles analyzed

The first question every new home mechanic asks: do I need metric or SAE sockets? The answer depends entirely on your vehicle. Buy the wrong set and half your bolts won't fit. Here's the definitive breakdown.

The Short Answer

• METRIC Japanese, Korean, and German vehicles — Toyota, Honda, Hyundai, Kia, Subaru, Mazda, Nissan, BMW, VW. All metric, all the time.
• SAE Older American vehicles — Pre-2000s GM, Ford, and Chrysler used mostly SAE (imperial) fasteners.
• BOTH Modern American trucks and muscle cars — Ford F-150, Chevy Silverado, Jeep Wrangler, Dodge Charger. These mix metric and SAE, so you need both socket sets.

Common Metric Sizes You'll Use

If your car is metric-only, these are the socket sizes you'll reach for most often:

• 10mm — The most-used (and most-lost) socket in any garage. Covers interior trim, brackets, battery terminals.
• 12mm — Splash shields, skid plates, small brackets.
• 14mm — Oil drain plugs (Toyota, Honda, Hyundai), brake caliper bolts on some models.
• 17mm — Brake caliper bracket bolts, suspension components.
• 19mm — Lug nuts on most Japanese vehicles.
• 21mm — Lug nuts on some larger SUVs and trucks.

Common SAE Sizes You'll Use

If your vehicle uses SAE fasteners (or a mix):

• 3/8" — Small brackets, trim pieces.
• 7/16" — Body bolts, older GM engines.
• 1/2" — Brake caliper bolts, various engine components.
• 9/16" — Wheel lugs on older trucks, suspension bolts.
• 3/4" — Axle nuts, large suspension bolts (close to 19mm).

Metric Only Vehicles (36)

These vehicles use metric fasteners exclusively. You do not need SAE sockets.

Metric & SAE Vehicles (19)

These vehicles use a mix of metric and SAE fasteners. You need both socket sets.

Frequently Asked Questions