Changing a tire is a relatively simple affair and most cars come with the equipment to perform the procedure as part of a basic vehicle-maintenance package. The car's owner's manual should also have instructions on where your tire changing equipment is located and the proper procedures.
A basic a tire changing kit typically includes:
- A jack
- A lug wrench with a socket on one end and a pry bar on the other
- A spare tire
Additional tools, depending on the make, model and year of your vehicle may include:
- A wheel lock
- Extension bars for lowering the spare tire
- Alignment studs
Jacks come in several varieties -- scissor jacks, floor jacks, bottle jacks and even bumper jacks. A scissor jack is the most common type and uses a mechanical scissor mechanism to lift the car. A bottle jack is more powerful but less compact and uses hydraulic fluid to lift the car.
The tire rim is held to the wheel hub by lug nuts screwed on to wheel studs. Before the spare tire can be fitted to the car the old rim and flat tire needs to be removed. Before this is accomplished, the lug nuts must be loosened and this is done with the lug wrench. A lug wrench is essentially a large socket wrench with one socket that matches the size of the lug nuts on your wheels. The length of the handle adds mechanical advantage -- the longer the handle, the more force you can exert on the nut. The pry bar on the other end is used to remove the hub cap and sometimes to pry the rim off the wheel hub if it's stuck on with rust or dirt.
Finally, there's the spare tire. Spares are either full-size or temporary (often called "donut" or "space saver") spares. A full-size spare offers more advantages as far as safety is concerned, but it's difficult to store, especially in smaller cars. It also weighs more and is harder to manage onto the wheel hub at ground level. A donut spare is easier to store and easier to manage on to the hub. However, it's generally less safe, usually limiting driving speed to less than 50 miles per hour (80.5 kilometers per hour) and a range of less than 60 miles (96.6 kilometers). Good car maintenance means checking the air pressure in the spare tire on a regular basis, too. It only takes a couple of minutes but may save you hours of aggravation someday.
The additional items listed are needed by certain cars rather than all cars. Wheel locks are a specially keyed lug nut socket designed to keep thieves from stealing your wheels. While a good idea, the locks are often lost, misplaced or simply disregarded until necessary -- but by then it's too late. If your car has wheel locks, tape the socket to the jack or to the inside of your glove box so it won't be lost.
Some car models store the spare under the car. The spare is lowered to the ground by turning a post that lowers the spare on a wire. This post is turned with an extension bar that's also used to help drag the spare out from under the car. This part of the car is often neglected during routine automotive maintenance. Every so often, and before long trips, make sure the spare will lower and the action on the mechanism is not rusted or corroded.
Many European cars use wheel bolts rather than wheel studs. Wheel studs stay on the hub and serve as a mounting surface for the spare. Wheel bolts screw into the hub and come off with the tire. With this type of system, putting the tire back on the car means having to manage the tire with a bolt through a rim hole and being able to wrestle the whole thing into position to screw the bolt in. This system is difficult to deal with even in controlled conditions, let alone on the side of a busy road. Wheel studs are a lot easier to deal with as the studs remain attached to the wheel hub and allow you to hang the tire on them and then replace the lug nuts.