Spare tire
A spare tire (including the spare tire ) is a car tire that carry most track vehicles. It is used for the exchange, when a car tire is defective.
As a rule, is a summer tire as the other mounted on the vehicle, available in a spare tire well in the trunk, sometimes under the vehicle. For cars but due to space, weight and price reasons a so-called Sparrad ( spare wheel ) is also used sometimes. The spare wheel may be used only until the next workshop, at a maximum speed of 80 km / h A special case of the spare wheel represents the folding bike dar. In contrast to that used in many manufacturers narrow spare wheel on a special rim, brand vehicles Porsche were delivered by the end of the nineties with folding bikes, initially on a standard steel rim (similar to the rims of the 1st generation of the Porsche 911) and were mounted on special lightweight alloy wheels since the late 1980s. Compared to conventional spare wheel has the folding bike, its tire wall once folded in half to fit between the rim flanges, the advantage that it is authorized pursuant to the original stiff or special rim for a top speed of 100 km / hr. The disadvantage is that the wheel has to be inflated before use only, since the sidewall is folded in the transport state, which is why these vehicles belonged to a powered 12 V low compressor. A recent development called breakdown kit is composed of a sealing liquid and a compressor to patch the tire and inflate poorly again. In addition, puncture resistant tires can be purchased for some time, which, through various methods, that in spite of a breakdown still can travel with a finite speed a short distance ( By now offer many tire manufacturers puncture proof tires, with whom you have to travel a certain distance without air can ( " SSR ", " Run Flat Tire ", " EMT "). All versions have in common is the fact that you should continue driving as short as possible, and with utmost caution to the next workshop, a new matching wheel leave to raise. This is particularly true for supposedly full replacement wheels that simply because of lack of or unverifiable air pressure no longer than strictly necessary should be used often because of a different make or profile, the wrong tire size or direction or.
In the normal checking the air pressure you should therefore always check the spare wheel, since it can lose air when not in use and in case of emergency then can not be used.
Tire change
To change the tire you need a jack and a wrench and a wheel wrench to loosen the wheel nuts and tighten it again. When lifting the car you have to secure it against rolling away by placing a wheel chock or a piece of wood. When changing a front wheel should also attract the handbrake.
When the truck to change certain wheel can often lift pneumatically.
Particularly problematic are flat tires on the drive axle in the winter. Since the spare wheel is usually carried out as a summer tire, it has decreased on snow roads liability. Remedy creates a double wheel change, that is, the spare tire is mounted on the non-driven axle and taken down, functional wheel on the drive axle. After a move off on snow and slopes is possible. This indicator should be changed at the earliest opportunity, as prescribed in Germany since 2006, adapted to the conditions of tires.
Statistics
The attempt by the motor vehicle industry, rationalize and replace it with a puncture repair kit, for example, the spare tire from cost, space and weight reasons, has failed so far in many cases the opposition of motorists. Many of them do not want to give up a spare or temporary spare wheel. So margins were due only about 3.3% to a puncture in 2010 from 4.25 million handled by the ADAC, while 16.2% came all alone by the battery existence.
Legal
In Germany it is not required by law to carry a reserve / spare wheel or tire repair kit in a motor vehicle. With external Ersätzrädern attached to motor vehicles special holders 3 traffic regulations are necessary in accordance with § 36a para.