You got a flat tire on the road and now you're standing beside your car wondering where to start. Changing a tire seems simple, but the sequence of steps matters - every skipped step can end with damage to the car or another stop two hundred meters down the road. Here's how to do it correctly, and which mistakes we regularly fix in our shop. Note: this applies to standard cars with a spare tire, not vehicles with run-flat tires or a puncture repair kit.
Before you jack up the car
Before you even touch the jack, do three things. First, pull the car as far off the road as possible, onto flat and firm ground. Soft soil, grass, or gravel are not surfaces for a jack - it sinks under load and the car can fall. If you're on a slope, engage first gear (or P for automatics) and the parking brake. It's also a good idea to place a rock or brick behind the wheel diagonally opposite the one you're changing, to prevent the car from rolling.
Second, take everything you need out of the trunk: the spare tire, the jack, the lug wrench, and if you have them, a warning triangle and reflective vest. Place the triangle behind the vehicle at the required distance. Third and most important: while the tire is still on the ground, loosen the lug bolts by half to one full turn. A wheel that's in the air spins freely and you can't loosen it - it just turns along with the wrench. This is mistake number one for drivers changing a tire for the first time. Loosen bolts counterclockwise, and sometimes serious force is needed because at tire shops they're often tightened with a pneumatic gun far above the specified torque.
Step-by-step replacement procedure
Once the bolts are loosened (not removed, just loosened), position the jack. Every car has a factory-marked jack point on the sill, usually indicated by a notch or small triangle on the plastic sill trim. This is a reinforced spot designed to bear the car's weight. Never place the jack on the engine undertray, on a suspension arm, or at a random point on the sill - you'll bend the sheet metal, damage the sill, and in the worst case the car can slip off the jack. If you're not sure where the jack point is on your model, check the owner's manual - the diagram is usually right in the tire change chapter.
Raise the car until the flat tire is 2-3 centimeters off the ground. No more than that, because the higher the car is raised, the less stable it is on the factory jack. Now remove the bolts completely, take off the flat tire, and put the spare in its place. Make sure the holes on the spare wheel line up with the studs on the hub. Thread the bolts in by hand until they seat in the thread, and only then tighten them with the wrench. But not in a circular order.
Bolt tightening sequence and torque
Bolts are tightened in a star pattern, meaning opposite bolts one after another. On a wheel with five bolts it looks like a star: tighten the top one, then the bottom left, then top right, then bottom right, then top left. With four bolts, go diagonally - first and third, then second and fourth. The goal is for the disc to seat evenly on the hub, without lateral pressure that would skew it to one side.
If you tighten bolts in a circular order, the disc shifts slightly. You might not notice it right away, but at higher speeds you'll feel vibrations in the steering wheel, and over time the brake discs can warp as well. Replacing a warped disc is incomparably more expensive than carefully tightening the bolts.
Tightening torque for most European cars is 110-130 Nm (Newton-meters, the unit of tightening force). There's a difference between steel and alloy wheels - alloy wheels usually require slightly higher torque, typically in the 120-140 Nm range. The exact figure is in your car's manual, usually on a sticker inside the spare tire cover or in the service booklet. You won't have a torque wrench on the road, but tighten the bolts evenly and with equal force, as much as you can. What matters is that this is temporary - within 24 hours you need to get to a shop or tire service to have the bolts torqued to spec.
Mistakes we see in the shop
The most common mistake we fix isn't from drivers on the road, but from tire shops with pneumatic guns. A pneumatic gun easily develops 200 or more Newton-meters, while the spec is 110-130. The result is stripped threads on the bolts or the hub, and that means an expensive replacement instead of routine tightening. If the tire shop doesn't use a torque wrench for the final tightening, that's a reason for concern.
The second common mistake is placing the jack in the wrong spot. We see bent sills, cracked plastic trim, and damage to the suspension and subframe because someone put the jack at a random point. Repairing a bent sill is needlessly expensive for something that could have been avoided with a single glance at the marking.
The third mistake is a spare tire that isn't ready. A spare tire in the trunk loses pressure over time, roughly 0.1-0.2 bar per month. The driver discovers it's flat exactly when they need it. Check the pressure in your spare tire at least once a year, ideally when you swap seasonal tires. Besides pressure, check the condition of the tire itself, because a tire that's been sitting in the trunk for years can have cracked sidewalls even if it's never been used.
When not to change it yourself and call for help instead
Don't attempt to change a tire on the highway in the passing lane or on a blind curve. If you can't get the car to a safe spot, call roadside assistance. The same goes if the jack is damaged, if you don't have a wrench of the right size, or if the bolts are so tight you can't loosen them - forcing them with a bad tool strips the threads.
If your car has run-flat tires (which can be driven on while flat for a short distance at reduced speed) or only a puncture repair kit instead of a spare tire, the procedure is completely different and is described in your model's manual. With such vehicles, roadside tire changing usually isn't even intended.
After you put on the spare tire and lower the car, drive carefully to the nearest shop or tire service. If it's a temporary spare (a space-saver), the speed limit is usually 80 km/h and it's not meant for long distances. Even with a full-size spare, the bolts aren't torqued to proper spec, so stop by the shop within a day to get it finished properly.