Will these fit my current wheels?

M12x1.5 is the most common metric thread size. Verify your original lug nut size before ordering — measure or check your owner's manual if unsure.

Do I need to replace all my lug nuts or just some?

Replace all five per wheel for consistency. This set covers four wheels (16 total) — you'll have four spares or use the lock nuts at one position per wheel.

Can I mix aluminum and steel lug nuts on the same wheel?

Not recommended. Stick with all aluminum or all steel per wheel to ensure even clamping force and prevent galvanic corrosion where different metals contact.