Faults, Replacement Rules, and Spares

Two fault signatures readable from the driver's seat:

• Steady pull to one side (steering held loosely, straight flat road) → wheel alignment — often a kerb or pothole strike; causes rapid uneven wear. (Distinguish from brake pull: alignment pulls always, brakes pull only when braking.)
• Steering-wheel vibration, often in a specific speed band → wheel balancing — accelerates wear, fatigues steering parts.

Both are cheap to fix and expensive to ignore — the tyre pays either way.

Replacement rules:

• Replace in axle pairs (one fresh beside one worn gives the axle two grip levels);
• re-tighten wheel bolts after several tens of km following any wheel change (bolts settle — a worked-loose wheel is catastrophe with a boring cause);
• retreads are legal and cheaper with potentially worse properties — a fleet economics fact, new rubber preferred for a private car.

Spares, three kinds: a full-size spare drives like any tyre (though a new tyre on one side impairs handling — refit the original when repaired); a temporary/space-saver is narrow and restricted, with a manual-specified max speed and distance, workshop-bound only; a puncture repair kit is a get-to-the-shop measure, nothing more.