ISO 18106:2026

• Abstract:

  This document specifies the method for measuring the relative snow grip performance index of a candidate tyre compared to a reference, under loaded conditions for new tyres intended to be used on passenger car, commercial vehicle, truck and bus vehicles on a snow packed surface. This document applies to all passenger car, commercial vehicle, truck and bus tyres.

• Status: Published
• Publication Date: 05-Aug-2026
• ICS: 83.160.10 - Road vehicle tyres
• Technical Committee: ISO/TC 31 - Tyres, rims and valves
• Drafting Committee: ISO/TC 31/WG 8 - Methods for measuring snow and ice grip performance
• Current Stage: 6060 - International Standard published
• Start Date: 06-Aug-2026
• Due Date: 03-Oct-2026
• Completion Date: 06-Aug-2026

• Revises: ISO 18106:2016 - Passenger car, commercial vehicle, truck and bus tyres — Methods for measuring snow grip performance — Loaded new tyres
• Effective Date: 28-Oct-2023

Overview

ISO 18106:2016 - Methods for Measuring Snow Grip Performance of Loaded New Tyres provides a globally recognized procedure for evaluating the snow traction capability of tyres fitted to passenger cars, commercial vehicles, trucks, and buses. Developed by the International Organization for Standardization (ISO), this standard establishes rigorous and consistent testing methods designed to minimize performance variability and ensure that snow grip assessments are reliable and reproducible. By using prescribed reference tyres and detailed procedures, ISO 18106 helps manufacturers and testing organizations assess the relative snow grip of new, loaded tyres intended for use on snow-packed surfaces.

Key Topics

• Scope of Application: Applies to all new tyres for passenger cars, commercial vehicles, trucks, and buses.
• Test Methods: Outlines standardized methods for braking and acceleration on snow:
  • Braking on snow for passenger car tyres
  • Braking on snow for commercial vehicle tyres
  • Acceleration on snow for truck and bus tyres
• Reference Tyres: Specifies the use of standard reference test tyres (SRTT) to limit variability in testing and enable fair comparisons.
• Performance Index: Snow grip performance is measured as a Snow Grip Index (SG), which compares the candidate tyre to the appropriate reference.
• Environmental Controls: Defines strict snow and temperature conditions for test courses to ensure repeatability.
• Statistical Validation: Requires the use of statistical tools to validate consistency and stability of test results, such as coefficient of variation and stability coefficients.

Applications

ISO 18106 is practically valuable for a range of stakeholders in the automotive and tyre industries:

• Tyre Manufacturers: Use this standard to benchmark new tyre models against internationally recognized criteria for snow performance, ensuring products meet consumer expectations and regulatory requirements.
• Testing Laboratories: Provides a reliable, standardized framework for conducting snow grip performance tests in controlled environments, supporting fair certification and product development processes.
• Regulatory Authorities: Facilitates the comparison of snow tyres for safety labeling, approvals, and market surveillance.
• Fleet Operators and Vehicle Manufacturers: Supports informed selection of tyres for vehicles expected to operate in snowy climates, improving road safety and operational efficiency.
• Consumer Safety Advocacy Groups: Access trustworthy information to recommend tyres with proven snow grip for winter driving conditions.

Related Standards

The effectiveness of ISO 18106 relies on several associated standards and reference documents, including:

• ISO 4000-1: Passenger car tyres and rims – Tyre definitions and specifications.
• ISO 4209-1: Truck and bus tyres and rims – Tyre specifications.
• ASTM F1805: Standard test method for measuring single wheel driving traction in a straight line on snow- and ice-covered surfaces.
• ASTM E1136: Specification for P195/75R14 radial standard reference test tyre (SRTT).
• ASTM F2870, F2871, F2872, F2493, F3677, F3678: Various standard specifications for reference test tyres, essential for consistent snow grip comparisons.

Practical Value

By standardizing the measurement of snow grip performance, ISO 18106 delivers numerous practical benefits:

• Ensures consistent, unbiased tyre performance assessments across different brands and models.
• Supports the development and certification of winter tyres with proven traction on packed snow.
• Enhances road safety for vehicles operating in cold and snowy regions.
• Enables global recognition of snow grip test results, simplifying regulatory compliance and market access.

Keywords: ISO 18106, snow grip performance, tyre testing, SRTT, passenger car tyres, truck tyres, bus tyres, commercial vehicle tyres, standard reference test tyre, snow traction, winter tyre standard, ISO tyre standards, brake and acceleration testing, vehicle safety.

International
Standard
ISO 18106
Second edition
Passenger car, commercial vehicle,
2026-08
truck and bus tyres — Methods for
measuring snow grip performance
— Loaded new tyres
Pneumatiques pour voitures particulières, véhicules utilitaires,
camions et autobus — Méthodes de mesurage de l´adhérence sur
neige — Pneumatiques neufs en charge
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test methods . 3
4.1 Braking on snow method for passenger car tyres .3
4.1.1 General .3
4.1.2 Test course .3
4.1.3 Vehicle .4
4.1.4 Standard reference test tyre (SRTT) .4
4.1.5 Tyres preparation .4
4.1.6 Tyre load .4
4.1.7 Tyre inflation pressure .4
4.1.8 Instrumentation.4
4.1.9 Testing order and sequences .4
4.1.10 Test procedure.5
4.1.11 Data evaluation and presentation of results .5
4.1.12 Snow grip performance comparison using a control tyre .7
4.2 Braking on snow method for commercial vehicle tyres .7
4.2.1 General .7
4.2.2 Test course .8
4.2.3 Vehicle .8
4.2.4 Standard reference test tyre (SRTT) .8
4.2.5 Tyres preparation .8
4.2.6 Tyre load .8
4.2.7 Tyre inflation pressure .8
4.2.8 Instrumentation.9
4.2.9 Testing order and sequences .9
4.2.10 Test procedure.9
4.2.11 Data evaluation and presentation of results .9
4.2.12 Snow grip performance comparison using a control tyre .9
4.3 Acceleration on snow method for truck and bus tyres .9
4.3.1 General .9
4.3.2 Test course .10
4.3.3 Vehicle .10
4.3.4 Standard reference test tyre (SRTT) .11
4.3.5 Tyres preparation .11
4.3.6 Tyre load .11
4.3.7 Tyre inflation pressure .11
4.3.8 Instrumentation.11
4.3.9 Testing order and sequences . 12
4.3.10 Test procedure. 13
4.3.11 Data evaluation and presentation of results .14
4.3.12 Snow grip performance comparison using a control tyre . 15
Annex A (informative) Example test report for a passenger car or commercial vehicle tyre .16
Annex B (informative) Example test report for a truck and bus tyre .18
Bibliography .20

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
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related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 31, Tyres, rims and valves.
This second edition cancels and replaces the first edition (ISO 18106:2016), which has been technically
revised.
The main changes are as follows:
— addition of the reference tyre ASTM F2493-24, SRTT P225/60R16;
— addition of new reference tyres ASTM F3677-23, SRTT 315/70R22.5 SW and ASTM F3678-25, SRTT
245/70R19.5 SW.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
The methods developed in this document are meant to reduce the variability of the tyre snow grip
performance measurement. The proper reference tyres must be used in order to limit the variability of the
testing method procedures.
v
International Standard ISO 18106:2026(en)
Passenger car, commercial vehicle, truck and bus tyres —
Methods for measuring snow grip performance — Loaded
new tyres
1 Scope
This document specifies the method for measuring the relative snow grip performance index of a candidate
tyre compared to a reference, under loaded conditions for new tyres intended to be used on passenger car,
commercial vehicle, truck and bus vehicles on a snow packed surface.
This document applies to all passenger car, commercial vehicle, truck and bus tyres.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 4000-1, Passenger car tyres and rims — Part 1: Tyres (metric series)
ISO 4209-1, Truck and bus tyres and rims (metric series) — Part 1: Tyres
ASTM E1136-19, Standard Specification for P195/75R14 Radial Standard Reference Test Tire
ASTM F1805-20, Standard Test Method for Single Wheel Driving Traction in a Straight Line on Snow- and Ice-
Covered Surfaces
ASTM F2872-25, Standard Specification for 225/75R16C 116/114S M+S Radial Light Truck Standard Reference
Test Tire
ASTM F2493-24, Standard Specification for P225/60R16 97S Radial Standard Reference Test Tire
ASTM F3677-23, Standard Specification for 315/70R22.5 154/150L Radial Truck Standard Reference Test Tire
SW
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
passenger car tyre
tyres conforming to ISO 4000-1
3.2
commercial vehicle tyre
tyres conforming to ISO 4209-1 and identified by a load index in single configuration lower or equal to 121
and a speed symbol higher or equal to “N”

3.3
truck and bus tyre
tyres conforming to ISO 4209-1 and identified by:
a) a load index in single configuration higher or equal to 122; or
b) a load index in single configuration lower or equal to 121 and a speed symbol lower or equal to “M”
3.4
test run
single pass of a loaded tyre over a given test surface
3.5
tyre set
group of two or four same tyres
3.6
candidate tyre
T
test tyre set (3.5) that is part of an evaluation program
3.7
reference tyre
R
special test tyre set (3.5), also known as a standard reference test tyre (SRTT), that is used as a benchmark
in an evaluation program
Note 1 to entry: In order to minimize their variation, these tyres have carefully controlled design features and are
produced, controlled and stored in accordance with the following ASTM standards:
— ASTM E1136-19, SRTT P195/75R14;
— ASTM F2870-23, SRTT 315/70 R 22.5 - 154/150 L;
— ASTM F2871-25, SRTT 245/70 R 19.5 - 136/134 M;
— ASTM F2872-25, SRTT 225/75 R 16 C - 116/114 S;
— ASTM F2493-24, SRTT P225/60R16 97 S;
— ASTM F3677-23, SRTT 315/70 R 22.5 SW - 154/150 L;
— ASTM F3678-25, SRTT 245/70 R 19.5 SW - 136/134 M.
3.8
control tyre
C
tyre set (3.5) that is part of an evaluation program
Note 1 to entry: It is an intermediate set of tyres which is used when the candidate tyre and the reference tyre cannot
be directly compared on the same vehicle.
3.9
braking test
series of a specified number of anti-lock braking system (ABS) braking test runs (3.4) of the same tyre
repeated within a short time frame
3.10
mean fully developed deceleration
MFDD
average deceleration calculated on the basis of the measured distance recorded when decelerating a vehicle
between two specified speeds
3.11
acceleration test
series of a specified number of traction-controlled acceleration test runs (3.4) of the same tyre repeated
within a short time frame
3.12
acceleration force of a tyre
longitudinal force resulting from acceleration torque application
Note 1 to entry: It is expressed in newtons, N.
3.13
acceleration force coefficient of a tyre
AFC
ratio of acceleration force of a tyre to its vertical load
3.14
average acceleration
AA
average acceleration calculated on the basis of the measured distance recorded when accelerating a vehicle
between two specified speeds
3.15
snow grip index
SG
ratio between the performance of the candidate tyre to the performance of the proper standard reference
test tyre
3.16
loaded radius
distance from wheel axis of rotation to supporting surface (ground) at a given load and stated inflation
pressure
4 Test methods
4.1 Braking on snow method for passenger car tyres
4.1.1 General
Snow performance is based on a test method by which the mean fully developed deceleration in a braking
test, of a candidate tyre is compared to that of a standard reference test tyre.
The relative performance shall be indicated by a snow grip index (SG) in a test report format as shown in
Annex A.
4.1.2 Test course
The braking tests shall be done on a flat test surface with a maximum 2 % gradient, covered with packed
snow.
The snow surface shall be composed of a hard-packed snow base at least 3 cm thick and a surface layer of
medium packed and prepared snow about 2 cm thick.
The air temperature, measured about one meter above the ground, shall be between −2 °C and −15 °C; the
snow temperature, measured at a depth of about one centimetre, shall be between −4 °C and −15 °C.
It is recommended to avoid direct sunlight, large variations of sunlight or humidity, as well as wind.
The snow compaction index shall be measured according to ASTM F1805-20 by using a CTI penetrometer.
The snow compaction index shall be between 75 and 85.

The candidate tyre should be tested in the same slope and snow compaction condition as the reference tyre
to avoid any advantage or disadvantage for the candidate tyre.
4.1.3 Vehicle
The test shall be conducted with a standard production vehicle in good running order and equipped with
ABS.
The vehicle used shall be such that the loads on each wheel are appropriate to the tyres being tested. Several
different tyre sets can be tested on the same vehicle.
4.1.4 Standard reference test tyre (SRTT)
The passenger car tyre snow grip performance shall be evaluated by using ASTM F2493-24, SRTT
P225/60R16 97S as the reference tyre.
4.1.5 Tyres preparation
Fit the test tyres on rims in accordance with ISO 4000-1 using conventional mounting methods. Ensure
proper bead seating by the use of a tyre industry accepted lubricant. Excessive use of lubricant should be
avoided to prevent slipping of the tyre on the wheel rim.
The tyres should be prepared prior to testing to remove spew, compound nodules or flashes resulting from
the moulding process. The tyre surface in contact with snow shall be clean before performing a test.
Tyres shall be conditioned at the outdoor ambient temperature at least two hours before their mounting for
tests. Tyre pressures shall then be adjusted to the values specified for the test.
In case a vehicle cannot accommodate both the reference and candidate tyres, a third tyre (“control” tyre)
may be used as an intermediate. First, test the control tyre against the reference on a vehicle, then test the
candidate tyre against the control on the other vehicle.
4.1.6 Tyre load
The vehicle load shall be such that the resulting loads on the tyres are between 60 % and 90 % of the load
corresponding to the tyre load index.
4.1.7 Tyre inflation pressure
The cold inflation pressure shall be 240 kPa.
4.1.8 Instrumentation
The vehicle shall be fitted with calibrated sensors suitable for measurements in winter conditions. There
shall be a data acquisition system to store measurements.
The accuracy of measurement sensors and systems shall be such that the relative uncertainty of the
measured or computed mean fully developed decelerations is less than 1 %.
4.1.9 Testing order and sequences
For every candidate tyre and the standard reference test tyre, ABS-braking test runs shall be repeated a
minimum of six times.
The zones where ABS-braking is fully applied shall not overlap.
When a new set of tyres is tested, the runs are performed after shifting aside the vehicle trajectory in order
not to brake on the tracks of the previous tyre.
When it is no longer possible not to overlap full ABS-braking zones, the test course shall be re-groomed.

The order of testing is as follows.
— If only one candidate tyre must be evaluated, the order of testing shall be as shown in Formula (1):
R - T - R (1)
i f
where
R is the initial test of the SRTT;
i
R is the repeat test of the SRTT;
f
T is the test of the candidate tyre to be evaluated.
— A maximum of two candidate tyres (T1 and T2) may be tested before repeating the SRTT test, for example
as shown in Formula (2):
R - T - T - R (2)
i 1 2 f
Required sequence is as follows:
— six SRTT repetitions, then shift aside to test next tyre on fresh surface;
— six candidate one repetitions, then shift aside;
— six candidate two repetitions, then shift aside;
— six SRTT repetitions, then shift aside.
The comparative tests of SRTT and candidate tyres shall be repeated on two different days.
4.1.10 Test procedure
Drive the vehicle at a speed not lower than 28 km/h.
When the measuring zone has been reached, the vehicle gear is set into neutral, the brake pedal is depressed
sharply by a constant force sufficient to cause operation of the ABS on all wheels of the vehicle and to result
in stable deceleration of the vehicle and held down until the speed is lower than 8 km/h.
The mean fully developed deceleration between 25 km/h and 10 km/h shall be computed from distance,
speed, or deceleration measurements.
The mean fully developed deceleration, MFDD, is given by Formula (3):

Sf −Si
(3)
2D
where
D is the distance covered between Si and Sf, in m;
Si is the initial speed, in m/s;
Sf is the final speed, in m/s.
4.1.11 Data evaluation and presentation of results
4.1.11.1 C
...