BMW 3 series E30

Since 1983-1994 of release

Repair and car operation

14.42. The scheme of marks of an automobile tyre

THE GENERAL DATA

1 – M&S (snow and a dirt). Marks specify that the tyre has a protector intended for winter conditions;
2 – reinforced, marks are entered for the reinforced tyres;
3 – requirements to loading and pressure (requirements not applicable in Great Britain);
4 – defines design type;
5 – a loading index;
6 – a symbol of speed;
7 – marks of type of quality of the tyre;
8 – the indicator of deterioration of a protector (marks are located not on all tyres);
9 – the out-of-date form of a designation of the size of the tyre, including a symbol of speed (S);
10 – marks and the code number of approbation of type ЕСЕ;
11 – details of a design of the tyre (in Great Britain are not required);
12 – the name of the manufacturer and the trade mark;
13 – the commercial name;
14 – a designation of the size of the tyre. New form ЕСЕ which the index of loading and a symbol of speed follows;
15 – a word "бескамерный" if it is applicable;
16 – the country-manufacturer;
17 – an acceptance symbol North American department of transport;
18 – the North American identifier of the tyre;
19 – designates a design tyres (radial).

Now tyres mark according to the standards co-ordinated with the European organisation on tyres and rims (ETRTO). Conditions and the requirements of today defined by the legislation, make manufacturers responsible for accurate definition of possibilities of the concrete tyre. Marks which define the maximum possibilities of the tyre on speed and load-carrying capacity, characteristic for certain service conditions are with that end in view entered.

The numerical code identifies ability of the tyre on load-carrying capacity at speed which is defined by a symbol of speed and under conditions which are defined by the manufacturer of the tyre. This code is called as a loading index (L.I.).

The symbol of speed defines speed from which the tyre can bear the loading corresponding to its index of loading, under conditions which are defined by the manufacturer of tyres.

The operational characteristic of the tyre includes a loading index (or two indexes of loading in case of unary/doubled installation) and a symbol of speed.

Automobile tyres

On the automobile tyre marks, as a rule, include one symbol of speed and one numerical index of loading, for example, 185/65 R 14 86 H MXV2.

185 – Nominal width of section in mm.

65 – the Indicator of section of the tyre.

R – the Radial design.

14 – Nominal diameter of a wheel in inches.

86 – a loading Index (load-carrying capacity makes 530 kg).

H – the Index of speed (i.e. speed to 210 km/hour, approximately 130 miles/hours).

MXV2 – Protector Drawing.

The reinforced tyres

These tyres, as well as at automobile, have data under operation characteristics, an index of loading and a symbol of speed. However the operation characteristic includes higher index of loading and lower symbol of speed in comparison with standard automobile tyres of the equivalent sizes. For example, 185 R 14 Reinforced (reinforced) 94 R: 185 R 14 90 Т.

High-quality tyres with a symbol of speed W

W is a new symbol of speed which has been entered by the Decision 30 ЕСЕ for the tyres maintained on speeds both to, and over 240 km/hour up to the maximum speed into 270 km/hour.

As well as in a case with a symbol speeds V, an index нгрузки these tyres it is established for lower speed; there is the certain decrease in load-carrying capacity expressed in percentage, on each 10 km/hour of increase in speed which in case of application of symbol W makes 5 %.

The full table of symbols of speed with applied percentage reduction грузоподъмности is more low resulted, there, where in that there is a necessity.

It is necessary to pay attention that tyres with a symbol of speed W can have as well marks ZR. As a result the size can be defined thus 225/50 ZR 16 83W or 225/50 R 16 83W.

V To 240 km/hour	SPEEDS, KM/H	LOAD-CARRYING CAPACITY OF THE TYRE
	210	100 %
	220	97 %
	230	94 %
	240	91 %
W To 270 km/hour	240	100 %
	250	95 %
	260	90 %
	270	85 %

If sign ZR is placed by the tyre within marks of the size and there are no other symbols of speed this tyre is intended for the speeds exceeding 240 km/hour more.

Older tyres with sign VR in marks of the size intended for speeds to and the exceeding 210 km/hour.

The note: Tyres into which dimensional marks signs VR or ZR enter only, are excluded from the Decision 30 ЕСЕ.

Tyres of vans and easy lorries

There is a big group of vehicles which from the point of view of tyres can be divided into three big groups:

1. Easy vans and pickups which represent direct development of the car.

2. Average vans and easy lorries which as those also have been designed, but very often use the basic components of cars.

3. The big vans and the small lorries using the chassis of a traditional vehicle.

All cars, except for the easiest vehicles from group 2 and 3, use tyres "With" for vans or (group 3) 17,5 inch cargo tyres.

Except for these rather big vehicles, all other vehicles from the given category use the standard or reinforced automobile tyres, and the majority of them concerns to 13 and 14 inch.

Other tyres for vans and utility trucks

Here various types of tyres which in the past marked only instructions of number of layers concern. For example, 185 R 14, 185 R 14 PR6 and 185 R 14 PR8.

Modern tyres of this category mark with instructions of operational characteristics, and is frequent and with instructions of a class of layers. (It is expected that the marks, concerning a class of layers, will be gradually cleaned).

In those cases, however, when the tyre can use on a back axis in a dual variant, apply two indexes of loading.

For example: 205 R 14 109/107 N

109 – a loading Index when the tyre is used in a single variant (1030 kg on the tyre)

107 – a loading Index when the tyre is used in a dual variant (975 kg on the tyre)