PCD, J, ET and centre bore

17 — rim diameter in inches. Fit a tyre with the same number: "R17" in its size.
7J — 7 is the rim width in inches: 7 × 25.4 = 177.8 mm. J is a code for the flange profile (the rim edge the tyre sits against), not a unit of width. J and JJ are the most common.
5 — number of bolt holes. Depending on the vehicle there are usually 4 to 6; a wheel with a different number of holes cannot be fitted.
114.3 — PCD: the diameter, in millimetres, of the circle through the centres of the hub bolts. A wheel with a different PCD cannot be fitted.
Offset 45 — explained in the next section.

Matching bolt holes and PCD alone do not confirm that the wheel fits. Check that the size, bolt holes, PCD, offset, mounting-face shape and nut seat all suit your vehicle.

If the mounting face is outboard of the centreline, the offset is positive; if inboard, negative. The plus sign may be omitted, so "ET45", "+45" and "offset 45" mean the same.

With the mounting face in the same place, a smaller offset moves the wheel outwards and a larger one moves it inwards. On the same 7J wheel, going from ET45 to ET35 moves the wheel 10 mm outwards. A large change can bring the tyre into contact with the wing or the brake caliper, and it affects handling stability. The offset number alone cannot tell you how much difference is acceptable: compare it with the vehicle's original wheels and check the clearance to the body and components.

The centre bore (DIA) is the diameter of the hole in the middle of the wheel. Compare it with the diameter of the vehicle's hub. Aftermarket wheels often have a larger centre bore, and the gap to the hub may be filled with a hub ring (hub collar). A hub ring cannot be fitted to every wheel design, and it must be removed when you go back to the original wheels or the spare.

Nuts and bolts: check the vehicle's thread diameter and pitch, and use fasteners that match the wheel's nut seat. Seats can be tapered, ball (spherical) or flat; fasteners of a different shape can come loose while driving.
Brakes and mounting face: on some vehicles, weights, assembly bolts or locating pins protrude from the brake drum or mounting face; check that they do not touch the wheel.
Body and suspension: after fitting, check for contact with the body and suspension parts — for the front wheels, also with the steering turned fully to each side. Wheels or tyres protruding beyond the body are prohibited by law.
Axles: if front and rear sizes differ, check both. Fit wheels of the same size and model on the same axle.
Standard: light-alloy wheels for passenger cars in Japan have a technical standard called JWL, and compliant wheels carry the JWL mark.
Tightening: tighten nuts and bolts to the recommended torque with a torque wrench, or to the value in the vehicle's manual if one is given. After fitting or rotating wheels, retighten them after about 100 km.

A vehicle name alone cannot confirm fitment: brakes and suspension of the same model can differ by year, chassis code and trim.

For used wheels, also check for signs of repair. A wheel maker's owner's manual warns that welding or straightening reduces a wheel's strength and can lead to air leaks, breakage and an accident, and says such repairs should not be made.