ISO 4000-1:1994

Passenger car tyres and rims — Part 1: Tyres (metric series)

Pneumatiques et jantes pour voitures particulières — Partie 1: Pneumatiques (série millimétrique)

General Information

• Status: Withdrawn
• Publication Date: 04-May-1994
• Withdrawal Date: 04-May-1994
• ICS: 83.160.10 - Road vehicle tyres
• Technical Committee: ISO/TC 31/SC 3 - Passenger car tyres and rims
• Drafting Committee: ISO/TC 31/SC 3 - Passenger car tyres and rims
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 14-Dec-1995

Relations

• Revised: ISO 4000-1:1995 - Passenger car tyres and rims — Part 1: Tyres (metric series)
• Effective Date: 15-Apr-2008
• Revises: ISO 4000-1:1989 - Passenger car tyres and rims — Part 1: Tyres (metric series)
• Effective Date: 15-Apr-2008
• Revises: ISO 4000-1:1985 - Passenger car tyres and rims — Part 1: Tyres (metric series)
• Effective Date: 15-Apr-2008

Standards Content (Sample)

I N TE R NAT I O NA L
IS0
STANDARD
4000- I
Fifth edition
1994-05-01
Passenger car tyres and rims -
Part 1:
Tyres (metric series)
Pneumatiques et jantes pour voitures particulières -
Partie I: Pneumatiques (série millimétrique)
Reference number
IS0 4000-1 :I 994(E)

---------------------- Page: 1 ----------------------
IS0 4000-1:1994(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 4000-1 was prepared by Technical Committee
31, Tyres, rims and valves, Sub-Committee SC 3, Passenger car
!SO/TC
tyres and rims.
This fifth edition cancels and replaces the fourth edition
(IS0 4000-1 :1989), of which it constitutes a technical revision.
IS0 4000 consists of the following parts, under the general title Passenger
car tyres and rims:
- Part I: Tyres (metric series)
- Part 2: Rims (metric series)
Annexes A and B form an integral part of this part of IS0 4000. Annexes
C and D are for information only.
O IS0 1994
All rights reserved. No part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without per-
mission in writing from the publisher.
International Organization for Standardization
Case Postale 56 CH-1 21 1 Genève 20 Switzerland
Printed in Switzerland
ii

---------------------- Page: 2 ----------------------
INTERNATIONAL STANDARD IS0 4000-1:1994(E)
Passenger car tyres and rims
1:
Part
Tyres (metric series)
a
1 Scope 4 Tyre designation
This part of IS0 4000 SF cifies th designati di-
4.1 Size and construction
mensions and load ratings of the metric series of
tyres primarily intended for passenger cars.
The characteristics shall be indicated as follows:
IS0 4000-2 deals with requirements for rims.
Nominal
rim diameter
width ratio code code
2 Normative references
4.1.1 Nominal section width
The following standards contain provisions which,
through reference in this text, constitute provisions
The nominal section width of the tyre shall be indi-
of this part of IS0 4000. At the time of publication, the
cated in millimetres, ending either in O or 5, so that in
editions indicated were valid. All standards are subject
any one series of tyres with the same nominal aspect
to revision, and parties to agreements based on this
ratio, the values shall all end with O or 5.
part of IS0 4000 are encouraged to investigate the
possibility of applying the most recent editions of the
0 For sizes mounted on 5" tapered (code-designated)
standards indicated below. Members of IEC and IS0
5.
rims, the nominal section width shall end with
maintain registers of currently valid International
Standards.
4.1.2 Nominal aspect ratio
IS0 31-0:1992, Quantities and units - Part O: Gen-
The nominal aspect ratio shall be expressed as a per-
eral principles.
centage and shall be a multiple of 5.
IS0 3877-1 :1978, Tyres, valves and tubes - List of
equivalent terms - Part 1: Tyres.
4.1.3 Tyre construction code
IS0 4000-2:1987, Passenger car tyres and rims -
The tyre construction code shall be as follows:
Part 2: Rims.
B for bias-belted construction;
IS0 4223-1 :1989, Definitions of some terms used in
the tyre industry - Part I: Pneumatic tyres.
D for diagonal construction;
R for radial ply construction.
3 Definitions
NOTE 1 Radial tyres designed for some existing vehicles
with maximum speed capabilities in excess of 210 km/h or
For definitions of terms relating to tyres, see
240 km/h may be designated and marked differently. See
IS0 4223-1 ; equivalent terms are given in IS0 3877-1. annex C.
1

---------------------- Page: 3 ----------------------
IS0 4000-1:1994(E)
characteristics is precluded. For the maximum speed
In the case of tyres designed for vehicles having a
capability and the load capacity of the tyres, the tyre
maximum speed capability in excess of 270 km/h, the
code-letters "ZR" shall be indicated in the dimensions manufacturer concerned shall be consulted.
and constructional characteristics for radial ply con-
struction in place of the tyre construction code R. (See
4.2.1 Load index
also 4.2.)
The maximum tyre load capacity corresponding to the
In the case of tyres designed for vehicles having a
service conditions specified by the tyre manufacturer
maximum speed capability of 240 km/h to 270 km/h,
shall be indicated by a load index taken from table2.
the code-letters "ZR" may be indicated in the dimen-
This indication is understood to be per tyre for a single
sional and constructional characteristics for radial ply
mounting.
construction in place of the tyre construction code R
(See example 2 and annex C.)
4.2.2 Speed symbol
NOTE 2 The use of another code letter (for example, in
the case of a new construction type) should first be remit-
The speed category is assigned to a tyre to denote
ted to IS0 for acceptance.
the maximum speed for which use of the tyre is
rated.
4.1.4 Nominal rim diameter code
The speed symbol shall be indicated by a letter taken
For tyres mounted on 5" tapered (code-designated)
from table3 corresponding to the speed category. 0
rims, the code shall be as given in table 1.
For tyres requiring new concept rims, for safety rea-
4.3 Other service Characteristics
sons especially concerning mounting, the code num-
ber shall be equal to the nominal rim diameter (DA,
expressed as a whole number of millimetres.
4.3.1 The word "TUBELESS" shall appear on the
tyre to characterize tyres that can be used without a
tube.
Table 1 - Nominal rim diameter code
Nominal rim diameter,
Nominal rim diameter
4.3.2 The letter "T" immediately in front of the tyre
Dr
code
size designation shall be used to characterize high-
mm
pressure special temporary-use spare tyres.
10 254
4.3.3 Specific indications, if required, may be added
12 305
to indicate:
13 330
356
14
- the type of vehicle for which the tyre is primarily
38 1
15 designed, using the symbol "P''l);
16 406
- the temporary use of certain spare tyres using in-
17 432
dications such as "TEMPORARY USE ONLY";
18 457
- the bias-belted construction with the words
19 483
" BIAS-B ELTED" ;
- the radial ply construction with the word
4.2 Service condition characteristics
"RADIAL";
The service condition characteristics or service de-
- the direction of mounting;
scription shall be indicated as follows:
- the direction of rotation;
Load index Speed symbol
For the special case of tyres designed for vehicles - the type of tread pattern;
having a maximum speed capability in excess of
270 km/h, the indication of the service condition - other characteristics.
1) This symbol may be used where there may be ambiguity regarding the tyre type. Where this optional marking is used, it
should be so positioned that confusion cannot result from its proximity to any other service condition marking.
2

---------------------- Page: 4 ----------------------
IS0 4000- 1 : 1994( E)
Table 2 - Correlation between load inde LI) and caDacitv
-
II
TLCC
TLCC
LI LI LI
kg kg
50 190 70 335 90 1 060
1 O90
51 195 71 345 91
1 120
52 200 72 355 92
206 73 365 93 1150
53
74 94 1 180
54 212 375
55 21 8 75 387 95 1215
224 76 400 96 1 250
56
57 230 77 41 2 97 1 285
58 236 78 425 98 1 320
99 1 360
59 243 79 437
1 O0 1 400
60 250 80 450
61 257 81 462 1 O1
62 265 82 475 102
103
63 272 83 487
64 280 84 500 104
65 290 85 51 5 105
86 530 106
66 300
67 307 87 545 107
68 31 5 88 560 108
1 O9
69 325 89 580
NOTES
1 The maximum tyre load capacity corresponding to the load index applies for speeds up to and including 210 km/h.
For speed symbol V tyres (between 210 km/h and 240 km/h), the maximum tyre load capacity is to be reduced to the fol-
lowing percentage:
1 O0 % at 21 O km/h;
97 % at 220 km/h;
94 % at 230 km/h;
91 % at 240 km/h.
Between these speeds, linear interpolation is permitted.
2 In the case of speed symbol W and ZR marked tyres, maximum load capacity corresponding to the load index applies
for speeds up to and including 240 km/h.
For speed symbol W tyres (between 240 km/h and 270 km/h), the maximum tyre load capacity is to be reduced to the
following percentage:
100 % at 240 km/h;
95 % at 250 km/h;
90 % at 260 km/h;
85 % at 270 km/h.
Between these speeds, linear interpolation is permitted.
For speeds over 270 km/h, consult the tyre manufacturer concerned for the maximum tyre load capacity permitted in re-
lation to the maximum speed allowed for the tyre.
3

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IS0 4000-1 :1994(E)
EXAMPLE 1
Table 3 - Correlation between speed symbol A tyre having
and speed category
a) a size and construction of:
Speed category
Speed symbol
km/h
- nominal section width 165 mm,
1 O0 - nominal aspect ratio 80,
J
110
K
- radial ply construction,
L 120
M 130
- nominal rim diameter code 15;
140
N
b) service condition characteristics of:
P 150
Q 160
- load index (LI) 87, corresponding to a tyre
R 170
load-carrying capacity of 545 kg,
S 180
- speed symbol H, corresponding to a speed
T 190
category of 21 O km/h;
U 200
H 210 c) other service characteristics:
v 240
- TUBELESS: tyre to be used without a tube;
W') 2701)
shall be marked as follows:
NOTE - This list is not restrictive; other categories may
165/80 R 15 87 H
be added later.
TUBELESS
1) Radial ply tyres designed for operations at speeds
NOTE 3 See annex D for other existing size markings.
in excess of 270 km/h are to be identified by means of
code-letters ZR in the "dimensional and
constructional" characteristics in place of the tyre con-
struction code. For these tyres, consult the tyre manu-
facturers concerned for the maximum speed capability.
EXAMPLE 2
A tyre marked
225145 ZR 16
5 Marking
has the following characteristics:
The marking shall consist of:
- nominal section width 225 mm;
a) the designation of the size and construction;
- nominal aspect ratio 45;
b) the designation of service condition character-
istics;2)
- radial ply construction tyre designed for operations
at speeds in excess of 270 km/h (code letters
c) the designation of other service characteristics.
"ZR ");
The location of the marking of the load and speed
- nominal rim diameter code corresponding to
characteristics shall be distinct, but near the marking
406 mm (code 16).
of the size and construction.
No location is specified for the markings related to NOTE 4 See annex C for special cases of radial tyres
designed for speeds in excess of 21 O km/h.
other service characteristics (see 4.3).
2) See special cases in 4.1.3 and 4.2.
4

---------------------- Page: 6 ----------------------
IS0 4000-1 :1994(E)
6.1.3 Design tyre section width, S
6 Tyre dimensions
The design tyre section width, S, is the nominal sec-
Except for the cases in 6.1.1 and 6.1.2, the formula-
tion width, s,, transferred from the theoretical rim,
derived values for tyre dimensions are to be rounded
Rth, to the measuring rim, R,:
to the nearest millimetre. For rounding, see IS0 31-0.
s = SN + 0,4(Rm -&)
Dimensions are expressed in millimetres.
NOTE 5
where R, and Rth are expressed in millimetres.
6.1 Calculation of "design tyre" dimensions
6.1.4 Design tyre section height, H
6.1.1 Theoretical rim width, Rth
The theoretical rim width, Rth, is equal to the product
The design tyre section height, H, is equal to the
of the nominal section width, S,, and the rimlsection
product of the nominal section width, S,, and the
ratio, Ki:
nominal aspect ratio, HIS, divided by 100:
Rth = KlsN
For tyres mounted on 5" rims (code-designated) with
nominal rim diameter expressed by a two-figure code,
6.1.5 Design tyre overall diameter, Do
K1 = 0,7 for tyres having nominal aspect ratio
(HIS) from 50 to 95 inclusive;
The design tyre overall diameter, Do, is the sum of the
nominal rim diameter, D,, plus twice the design tyre
K1 = 0,85 for tyres having nominal aspect ratio
section height, H:
(HIS) from 35 to 45 inclusive.
Do = D,+2H
Other K1 values will be defined later for other tyre and
rim types. For those tyres using a nominal rim diameter code,
the corresponding value of D, given in table 1 is to be
used.
6.1.2 Measuring rim width, R,
The measuring rim width, is equal to the product
6.1.6 Guidelines
of the nominal section width, SN, and the rimlsection
width ratio coefficient, K2:
Guidelines for the ('tyre design dimensions" for the
R, = K~SN
metric series of passenger car tyres mounted on 5"
rims (code-designated) are given in annex A. Table5
rounded to the nearest standardized rim.
presents a guide relating to the determination of the
appropriate rim widths for a given tyre.
For tyres mounted on 5" drop-centre rims with a
nominal diameter expressed by a two-figure code,
6.2 Calculation of "maximum overall
K2 = 0,7 for nominal aspect ratios (HIS) 95 to 75
inclusive; (grown) tyre dimensions in service"
K2 = 0,75 for nominal aspect ratios (HIS) 70 to 60 This calculation is for use by vehicle manufacturers in
inclusive; designing for tyre clearance.
These dimensions are to be calculated with the coef-
K2 = 0,8 for nominal aspect ratios (HIS) 55 to 50
ficients (see table41 appropriate to the design tyre
inclusive;
section width and design tyre section height.
K2 = 0,85 for nominal aspect ratio (HIS) 45;
6.2.1 Maximum overall (grown) width in service.
K2=0,9 for nominal aspect ratios (HIS) 40 to 35
Wmax
inclusive.
The maximum overall (grown) width in service, Wmax,
Other values of K2 will be defined later for other tyre
is equal to the greater of the two following values:
and rim types.
5
R,,

---------------------- Page: 7 ----------------------
IS0 4000-1:1994(E)
Table 4 - Coefficients for calculation of tyre dimensions
Nominal Nominal aspect aspect
Coefficients Coefficients
Tyre Tyre construction construction ratio ratio
Structure Structure
code code
HIS HIS a a 1) 1) b C d
lblcld
- - - -
Diagonal Diagonal D D
All All 1,1 1,1 1 1 ,O8 ,O8
- - _. _.
Bias-belted Bias-belted B B
Q Q 65 65 1,042) 1,042)
Radial Radial ply ply R R 70 70 1,043) 1,043) 1 1 ,O4 ,O4 0,96 0,96 0,97 0,97
2 2 75 75 1 1 ,O6 ,O6
1) The maximum overall section width may be exceeded by the thickness of a special protective rib on one sidewall.
2) Application as of January lst, 1992.
3) Application as of January lçt, 1995.
a) the product of the design tyre section width, S, 6.3.2 Minimum tyre overall diameter, Do,,,,,
and the appropriate coefficient, a (see table 4):
The minimum tyre overall diameter, Do,,in, is equal to
w,,, = Sa
the nominal rim diameter, D,, plus twice the product
of the design tyre section height, H, and the coef-
b) the addition of 8 mm to the design tyre section
ficient d (see table4):
width, S:
Do,,in = D, + 2Hd
W,,, = S+8
6.4 Range of recommended rims
6.2.2
...

I NTE R NAT I O NA L
IS0
STANDARD
4000-1
Fifth edition
1994-05-01
Passenger car tyres and rims -
Part 1:
Tyres (metric series)
Pneumatiques et jantes pour voitures particulières -
Partie I: Pneumatiques (série millimétrique)
~.
" -
l"_l__
Reference number
IS0 4000-1 11 994(E)

---------------------- Page: 1 ----------------------
IS0 4000-1:1994(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
(IS0 member bodies). The work
federation of national standards bodies
of preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(I EC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 4000-1 was prepared by Technical Committee
!SO/TC 31, Tyres, rims and valves, Sub-committee SC 3, Passenger car
tyres and rims.
This fifth edition cancels and replaces the fourth edition
(IS0 4000-1 :1989), of which it constitutes a technical revision.
IS0 4000 consists of the following parts, under the general title Passenger
car tyres and rims:
- Part 7: Tyres (metric series)
- Part 2: Rims (metric series)
Annexes A and B form an integral part of this part of IS0 4000. Annexes
D are for information only.
C and
0 IS0 1994
All rights reserved. No part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without per-
mission in writing from the publisher.
international Organization for Standardization
Case Postale 56 CH-1 21 1 Genève 20 Switzerland
Printed in Switzerland
II

---------------------- Page: 2 ----------------------
INTERNATIONAL STANDARD IS0 4000-1 :1994(E)
Passenger car tyres and rims
Part 1:
Tyres (metric series)
0
1 Scope 4 Tyre designation
This part of IS0 40,- specifies the usignation, (
4.1 Size and construction
mensions and load ratings of the metric series of
tyres primarily intended for passenger cars.
The characteristics shall be indicated as follows:
IS0 4000-2 deals with requirements for rims.
Nominal
rim diameter
width ratio code code
2 Normative references
4.1.1 Nominal section width
The following standards contain provisions which,
through reference in this text, constitute provisions
The nominal section width of the tyre shall be indi-
of this part of IS0 4000. At the time of publication, the
cated in millimetres, ending either in O or 5, so that in
editions indicated were valid. All standards are subject
any one series of tyres with the same nominal aspect
to revision, and parties to agreements based on this
O or 5.
ratio, the values shall all end with
part of IS0 4000 are encouraged to investigate the
possibility of applying the most recent editions of the
For sizes mounted on 5" tapered (code-designated)
standards indicated below. Members of IEC and IS0
rims, the nominal section width shall end with 5.
maintain registers of currently valid International
Standards.
4.1.2 Nominal aspect ratio
IS0 31-0:1992, Quantities and units - Part O: Gen-
The nominal aspect ratio shall be expressed as a per-
eral principles.
centage and shall be a multiple of 5.
IS0 3877-1 : 1978, Tyres, valves and tubes - List of
equivalent terms - Part 1: Tyres.
4.1.3 Tyre construction code
IS0 4000-2: 1987, Passenger car tyres and rims -
The tyre construction code shall be as follows:
Part 2: Rims.
B for bias-belted construction;
IS0 4223-1 :1989, Definitions of some terms used in
the tyre industry - Part I: Pneumatic tyres.
D for diagonal construction;
R for radial ply construction.
3 Definitions
NOTE 1 Radial tyres designed for some existing vehicles
with maximum speed capabilities in excess of 210 km/h or
For definitions of terms relating to tyres, see
240 km/h may be designated and marked differently. See
IS0 4223-1 ; equivalent terms are given in IS0 3877-1. annex C.
1

---------------------- Page: 3 ----------------------
IS0 4000-1 :1994(E)
In the case of tyres designed for vehicles having a characteristics is precluded. For the maximum speed
maximum speed capability in excess of 270 km/h, the capability and the load capacity of the tyres, the tyre
code-letters "ZR" shall be indicated in the dimensions manufacturer concerned shall be consulted.
and constructional characteristics for radial ply con-
struction in place of the tyre construction code R. (See
4.2.1 Load index
also 4.2.)
The maximum tyre load capacity corresponding to the
In the case of tyres designed for vehicles having a
service conditions specified by the tyre manufacturer
maximum speed capability of 240 km/h to 270 km/h,
shall be indicated by a load index taken from table2.
the code-letters "ZR" may be indicated in the dimen-
This indication is understood to be per tyre for a single
sional and constructional characteristics for radial ply
mounting.
construction in place of the tyre construction code R
(See example 2 and annex C.)
4.2.2 Speed symbol
NOTE 2 The use of another code letter (for example, in
the case of a new construction type) should first be remit-
The speed category is assigned to a tyre to denote
ted to IS0 for acceptance.
is
the maximum speed for which use of the tyre
rated.
4.1.4 Nominal rim diameter code
The speed symbol shall be indicated by a letter taken
For tyres mounted on 5" tapered (code-designated)
from table3 corresponding to the speed category. 0
rims, the code shall be as given in table 1.
For tyres requiring new concept rims, for safety rea-
4.3 Other service characteristics
sons especially concerning mounting, the code num-
ber shall be equal to the nominal rim diameter (QI,
expressed as a whole number of millimetres.
4.3.1 The word "TUBELESS" shall appear on the
tyre to characterize tyres that can be used without a
tube.
Table 1 - Nominal rim diameter code
Nominal rim diameter,
Nominal rim diameter
4.3.2 The letter "T" immediately in front of the tyre
Dr
code
size designation shall be used to characterize high-
mm
pressure special temporary-use spare tyres.
10 254
4.3.3 Specific indications, if required, may be added
12 305
to indicate:
13 330
14 356
- the type of vehicle for which the tyre is primarily
15 381
designed, using the symbol ''P"l);
16 406
- the temporary use of certain spare tyres using in- e
17 432
dications such as "TEMPORARY USE ONLY";
18 457
- the bias-belted construction with the words
19 483
" B I AS-B E LTE D " ;
- the radial ply construction with the word
4.2 Service condition characteristics
"RADIAL";
The service condition characteristics or service de-
- the direction of mounting;
scription shall be indicated as follows:
- the direction of rotation;
Load index Speed symbol
For the special case of tyres designed for vehicles - the type of tread pattern;
having a maximum speed capability in excess of
270 km/h, the indication of the service condition - other characteristics.
1) This symbol may be used where there may be ambiguity regarding the tyre type. Where this optional marking is used, it
should be so positioned that confusion cannot result from its proximity to any other service condition marking.
2

---------------------- Page: 4 ----------------------
IS0 4000-1 :1994(E)
Table 2 - Correlation between load index ILI) and i re load-carrying capacity rLcc)
TLCC TLCC TLCC TLCC
LI LI LI LI
kg kg kg
110
50 190 70 335 90 600 1 060
51 195 71 345 91 61 5 111 1 O90
200 72 355 92 112 1 120
52 630
53 206 73 365 93 650 113 1 150
54 21 2 74 375 94 670 114 1 180
115 1215
55 21 8 75 387 95 690
56 224 76 400 96 71 O 116 1 250
230 77 730 117 1 285
57 41 2 97
236 118 1 320
58 78 425 98 750
59 243 79 437 99 775 119 1 360
60 250 80 450 1 O0 800 120 1 400
61 257 81 462 1 O1 825
62 265 82 475 102 850
63 272 83 487 103 875
900
64 280 84 500 104
65 290 85 51 5 105 925
66 300 86 530 106 950
67 307 87 545 107 975
31 5 88 560 108 1 O00
68
69 325 89 580 1 O9 1 030
NOTES
1 The maximum tyre load capacity corresponding to the load index applies for speeds up to and including 21 O km/h.
For speed symbol V tyres (between 210 km/h and 240 km/h), the maximum tyre load capacity is to be reduced to the fol-
lowing percentage:
100 % at 210 km/h;
97 % at 220 km/h;
94 % at 230 km/h;
91 % at 240 km/h.
Between these speeds, linear interpolation is permitted.
2 In the case of speed symbol W and ZR marked tyres, maximum load capacity corresponding to the load index applies
for speeds up to and including 240 km/h.
For speed symbol W tyres (between 240 km/h and 270 kmlh), the maximum tyre load capacity is to be reduced to the
following percentage:
100 % at 240 km/h;
% at 250 km/h;
95
90 % at 260 km/h;
85 % at 270 km/h.
Between these speeds, linear interpolation is permitted.
For speeds over 270 km/h, consult the tyre manufacturer concerned for the maximum tyre load capacity permitted in re-
lation to the maximum speed allowed for the tyre.
3

---------------------- Page: 5 ----------------------
IS0 4000-1:1994(E)
EXAMPLE 1
Table 3 - Correlation between speed symbol
A tyre having
and sneed category
a) a size and construction of:
Speed category
Speed symbol
km/h
- nominal section width 165 mm,
- nominal aspect ratio 80,
J 1 O0
K 110
- radial ply construction,
L 120
M 130
- nominal rim diameter code 15;
N 140
b) service condition characteristics of:
P 150
0 160
- load index (LI) 87, corresponding to a tyre
R 170
load-carrying capacity of 545 kg,
S 180
- speed symbol H, corresponding to a speed
T 190
category'of 21 O km/h;
0
200
U
H 21 O c) other service characteristics:
V 240
- TUBELESS: tyre to be used without a tube;
W1) 2701)
shall be marked as follows:
NOTE - This list is not restrictive; other categories may
165180 R 15 87 H
be added later.
TUBELESS
1) Radial ply tyres designed for operations at speeds
in excess of 270 km/h are to be identified by means of NOTE 3 See annex D for other existing size markings.
code-letters ZR in the "dimensional and
constructional" characteristics in place of the tyre con-
struction code. For these tyres, consult the tyre manu-
facturers concerned for the maximum speed capability.
EXAMPLE 2
A tyre marked
5 Marking 225145 ZR 16
has the following characteristics:
The marking shall consist of:
- nominal section width 225 mm;
a) the designation of the size and construction;
- nominal aspect ratio 45;
b) the designation of service condition character-
istics;*'
- radial ply construction tyre designed for operations
at speeds in excess of 270 km/h (code letters
c) the designation of other service characteristics.
" ZR " 1 ;
The location of the marking of the load and speed
- nominal rim diameter code corresponding to
characteristics shall be distinct, but near the marking
406 mm (code 16).
of the size and construction.
No location is specified for the markings related to See annex C for special cases of radial tyres
NOTE 4
designed for speeds in excess of 210 km/h.
other service characteristics (see 4.3).
2) See special cases in 4.1.3 and 4.2.
4

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IS0 4000-1:1994(E)
6.1.3 Design tyre section width, S
6 Tyre dimensions
The design tyre section width, S, is the nominal sec-
Except for the cases in 6.1.1 and 6.1 2, the formula-
tion width, s,, transferred from the theoretical rim,
derived values for tyre dimensions are to be rounded
Rth, to the measuring rim, R,:
to the nearest millimetre. For rounding, see IS0 31-0.
s = SN -t 0,4(R, - Rth)
NOTE 5 Dimensions are expressed in millimetres.
where R, and Rth are expressed in millimetres.
6.1 Calculation of "design tyre" dimensions
6.1.1 Theoretical rim width, Rth 6.1.4 Design tyre section height, H
The theoretical rim width, Rth, is equal to the product
The design tyre section height, H, is equal to the
of the nominal section width, S,, and the rim/section
product of the nominal section width, SN, and the
ratio, Ki:
nominal aspect ratio, HIS, divided by 100:
Rth = KlsN HIS
1 O0
For tyres mounted on 5" rims (code-designated) with
nominal rim diameter expressed by a two-figure code,
e
6.1.5 Design tyre overall diameter, Do
Ki = 0,7 for tyres having nominal aspect ratio
(H/S) from 50 to 95 inclusive;
The design tyre overall diameter, Do, is the sum of the
nominal rim diameter, D,, plus twice the design tyre
K1 = 0,85 for tyres having nominal aspect ratio
section height, H:
(HIS) from 35 to 45 inclusive.
Do = D, + 2H
Other Ki values will be defined later for other tyre and
rim types. For those tyres using a nominal rim diameter code,
the corresponding value of D, given in table 1 is to be
used.
6.1.2 Measuring rim width, R,
The measuring rim width, R,, is equal to the product
6.1.6 Guidelines
of the nominal section width, S,, and the rim/section
width ratio coefficient, K2:
Guidelines for the ('tyre design dimensions" for the
R, = K~SN
metric series of passenger car tyres mounted on 5"
rims (code-designated) are given in annex A. Table5
rounded to the nearest standardized rim.
presents a guide relating to the determination of the
appropriate rim widths for a given tyre.
For tyres mounted on 5" drop-centre rims with a
I) nominal diameter expressed by a two-figure code,
6.2 Calculation of "maximum overall
K2 = 0,7 for nominal aspect ratios (HIS) 95 to 75
inclusive; (grown) tyre dimensions in service"
K2 = 0,75 for nominal aspect ratios (HIS) 70 to 60 This calculation is for use by vehicle manufacturers in
inclusive; designing for tyre clearance.
These dimensions are to be calculated with the coef-
K2 = 0,8 for nominal aspect ratios (HIS) 55 to 50
ficients (see table41 appropriate to the design tyre
inclusive:
section width and design tyre section height.
K2 = 0,85 for nominal aspect ratio (HIS) 45;
6.2.1 Maximum overall (grown) width in service,
K2 = 0,9 for nominal aspect ratios (HIS) 40 to 35
Wmax
inclusive.
Other values of K2 will be defined later for other tyre The maximum overall (grown) width in service, Wmax,
is equal to the greater of the two following values:
and rim types.
5

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IS0 4000-1:1994(E)
Table Table 4 4 - - Coefficients Coefficients for for calculation calculation of of tyre tyre dimensions dimensions
I 1 I
Nominal Nominal aspect aspect
Coefficients Coefficients
Tyre Tyre construction construction ratio ratio
Structure Structure
code code
HIS HIS a a 1) 1) b b C C d d
- - - -
Diagonal Diagonal D D
All All 1 1 ,I ,I 1 1 ,O8 ,O8
- - - -
Bias-belted Bias-belted B B
B B 65 65 1,042) 1,042)
Radial Radial ply ply R R 70 70 1 1 ,O4 ,O4 3) 3) 1 1 ,O4 ,O4 0,96 0,96 0,97 0,97
2 2 75 75 1 1 ,O6 ,O6
1) The maximum overall section width may be exceeded by the thickness of a special protective rib on one sidewall.
2) Application as of January Ist, 1992.
3) Application as of January Ist, 1995.
a) the product of the design tyre section width, S,
6.3.2 Minimum tyre overall diameter, Do,min
and the appropriate coefficient, a (see table4):
The minimum tyre overall diameter, is equal to
w,,, = Sa
the nominal rim diameter, D,, plus twice the product
of the design tyre section height, H, and the coef-
b) the addition of 8 mm to the design tyre section
ficient d (see table4):
width, S:
Do,min = D, + 2Hd
W,,,=S+8
6.4 Range of recommended rims
6.2.2 Maximum overall (grown) diameter in
service, Do,,,,
6.4.1 The range of recommended rim widths is cal-
culated as the product of the nominal section width,
The maximum overall (grown) diameter in service,
S,, and the coefficients shown in table5. The
...