Do I need to calibrate this wrench before use?

New torque wrenches should be checked against a known standard before critical work. If you're working on suspension or brake hardware, a quick calibration check at a local shop is cheap insurance.

Can I use this on my lug nuts?

Depends on your vehicle's spec. Many passenger cars run 80-100 ft-lbs, which is outside this wrench's range. Check your service manual first — this one excels at smaller fasteners like caliper bolts, control arm hardware, and engine bay work.

What socket size do I need?

This wrench has a 1/4" square drive, so you'll need 1/4" drive sockets. Common sizes for automotive work are 5mm, 6mm, 8mm, and 10mm — but verify your specific fasteners before ordering.