Fig. 325. Marks of tyres

On a lateral surface of tyres there are marks from a lot of figures and letters which serve for experts as the coded card. The majority of drivers the sizes of tyres interest only. 175/70 R14 means that the cross-section section of the tyre on width has the size of 175 mm. The second figure shows the attitude of height of a profile to width of the tyre in percentage. In set an example it makes 70 %. The less this parity, the the tyre is wider. The letter R — an index of the radial tyre, and last number "14" shows landing diameter of the tyre in inches (fig. 325).

High-speed index

The capital letter behind last figure on a lateral surface of the tyre means admissible speed for this tyre. The tyre 175/70 R 14 with a designation S is admissible for speed to 180 km/h, with Т — to 190 km/h. For as much as possible admissible speed of 210 km/h there is a designation Н. Usual tyres with М+S or in abbreviated form Q, are intended for operation with a speed of 160 km/h.

Number DOT shows manufacturing date

Number DOT on a lateral surface of the tyre shows the valid date of manufacturing. Since 1990 behind this designation there is a small triangle. For example, number DOT 1500 means that the tyre is made on 15 week 2000 New tyres with 10/1/1998 should to have on a lateral surface code ЕСЕ. Each code guarantees that the tyre is made according to the standard of the European economic commission (ЕСЕ-R30). If on tyres of your car costs DOT and its number more than 408 — but without ЕСЕ the standard – means that the car is maintained without the general permission to operation.

Winter tyres

Fig. 326. Comparison of a brake way with summer and winter tyres without ABS

Fig. 327. Comparison of a brake way with summer and winter tyres with ABS

Winter tyres are made of special structure with the high maintenance of natural rubber. This special structure on wet and slippery road has the best coupling characteristics, than summer tyres. In any case put winter tyres only on all four wheels — the combination of winter and summer tyres is inadmissible because of safety reasons (fig. 326 and 327).

Installation of winter tyres

Good winter tyres should not be wide, winter tyres with the smallest sizes will be enough for your car. Besides, small tyres are cheaper, than big, thus you can save means for acquisition of the second complete set of disks for winter tyres. Constant replacement of summer tyres by the winter does not do them better, and finally it to you will cost dearer, than the second complete set of disks. Besides, after each installation of a wheel should be balanced again. Support pressure in winter tyres on 20 кПа above, than in the summer. If the high-speed characteristic of the winter tyre below speed limit of your car, it is necessary to paste warning sign on a windscreen foreground. Sellers of tyres, as a rule, have such labels.

Recommendations about increase in service life of tyres:

- Do not exceed speed of movement more admissible under the certificate on tyres. It first of all concerns to M+S to category tyres Q (160 km/h). Too high speed is at the bottom of an overload that at worst can lead to tyre rupture;

- Avoid the big speeds at a car total load. Check up tyre heating, if the tyre нагрета to the temperature supposing a touch of a hand, with it everything is all right. Too hot tyre hides danger, often it occurs because of low pressure in tyres or damages of a skeleton of the tyre. Do not trust such tyres in a way — at least till the moment while the expert will not check up a skeleton on presence of damages;

- If you, as a rule, go on high-speed lines, establish tyres with бо2льшим a high-speed index, than it is required in the maintenance instruction of your car (for example, Т instead of S);

- Pay attention at a parking to edges бордюрных of stones. If move бордюрные stones or cross ties do it slowly;

- Pressure increase in tyres on 30 кПа saves fuel.

Correct replacement of wheels

If at the first replacement of wheels you have decided to put a new spare wheel you save cash. Provided that tyres with a similar profile still are issued. In this case you buy one more wheel and establish. You can raise service life of your wheels in addition still: regularly interchange the position of wheels on one party of the car, lobbies on back and on the contrary. Pay attention at replacement of tyres by that on one axis there were tyres of one manufacturer, with an identical protector and identical date of manufacture ( year).

Pressure in cold tyres, кПа

Model	The size шин*	Normal loading to 3 persons		Full loading from above 3 persons
		Lobbies	The back	Lobbies	The back
Limousine/Turnier	175/70 R14	220	220	220/240 **	310
	185/60 R14	220	220	220/240 **	310
	195/60 R15	220	220	220/230 **	310
	195/55 R15	200	200	220/250 **	310
	205/50 R16	220	220	220/240 **	310
	125/80 R15 ***	420	420	420	420

* Summer tyres.

** The car with the diesel engine.

*** Spare wheel.

At a long trip with a speed of 160 km/h pressure increases on 20 кПа.

Pressure check in tyres

Fig. 328. Because of the lowered pressure of the tyre superficial destruction too heats up and turns out

Pressure in tyres is checked only on cold as during a tyre trip heat up also pressure raises (fig. 328). Check pressure regularly each three-four weeks, loss of pressure upon 1,5 % every month it it is normal.

Close the gate of the chamber a cap

The gate of the chamber after each check of pressure should be closed by a cap as if once the dirt gets to the gate, durability of consolidation in this place will be broken — tyres will constantly lose air. Try to avoid trips at too small pressure in tyres — the temperature of tyres can pass admissible norm. Sooner or later it can lead соскакиванию tyres from a disk or the tyre can burst. It is better, that pressure in tyres was a bit more (approximately on 20-30 кПа) that offers the advantages: the steering becomes more obedient, tyres serve longer and the fuel expense decreases. A lack: smoothness of a course of the car a little decreases.