As soon as you notice you have a flat tyre, slow down and find a safe place to stop on a firm, flat surface.
If you’re on the motorway, however, move to the hard shoulder and phone for a recovery truck for help – it’s too dangerous to change a tyre there.
How to change a flat tyre – the safe way
If it is safe to do so, find the spare wheel, the jack and the wheel wrench, which will all hopefully be under the boot floor, under the car or on the back door. No spare wheel! If you can’t find a spare wheel, your car may instead be equipped with inflating mousse that can be squirted into the tyre through the valve. This is only a temporary solution to get you home, though, and you should still get the tyre changed as soon as possible.
To remove the punctured tyre, loosen the wheel nuts with the wheel wrench, but don’t remove them. If you can’t see the wheel nuts, you may have to first prise off a wheel cover.
Then, check that the handbrake is firmly on and put the car into first gear. Find the jacking point by looking in your car’s manual, and use the jack to raise the car so that the wheel is just off the ground.
Now fully remove the wheel nuts and take off the wheel. It may need a sharp knock to dislodge it, but be very careful not to destabilise the jack as the car could come crashing down.
Lift the spare wheel onto the wheel hub, line up the holes and screw in the nuts.
Once the wheel is secure, lower the jack and use the wrench to tighten the wheel nuts fully.
Check them all twice before packing up and heading to the nearest garage to get the old tyre fixed or replaced.