Changing a flat tyre safely, and when not to

Most people can change a wheel. The question is whether they should, where they are standing.

When to wait for help instead

• The flat is on the traffic side of the car
• You are on a highway, a bridge or a road with no shoulder
• The ground is soft, sloped or dark
• The wheel nuts will not move, or the locking-nut key is missing
• There is no spare, only a repair kit, and the damage is on the sidewall

If you are somewhere safe and flat

1. Handbrake on, in gear or in Park, hazards on
2. Loosen each wheel nut half a turn while the wheel is still on the ground
3. Jack at the marked jacking point only, never under the floor pan
4. Swap the wheel, snug the nuts in a star pattern, lower the car, then tighten fully
5. Check the spare's pressure; many have been flat for years
6. Space-saver spares are for short distances at reduced speed, usually under 80 km/h or 50 mph

Repair or replace?

A clean puncture in the tread of a tubeless tyre, from a nail or screw, can usually be plugged. Cuts in the sidewall, bulges and damage from driving flat cannot be repaired safely.