ISO 362-1:2022

Acoustics - Engineering method for measurement of noise emitted by accelerating road vehicles - Part 1: M and N categories

This document specifies an engineering method for measuring the noise emitted by road vehicles of categories M and N under typical urban traffic conditions. It excludes vehicles of category L1 and L2, which are covered by ISO 9645, and vehicles of category L3, L4, and L5, which are covered by ISO 362‑2. The specifications are intended to reproduce the level of noise generated by the principal noise sources during normal driving in urban traffic (see Annex A). The method is designed to meet the requirements of simplicity as far as they are consistent with reproducibility of results under the operating conditions of the vehicle. The test method requires an acoustical environment that is obtained only in an extensive open space. Such conditions are usually provided for - type approval measurements of a vehicle, - measurements at the manufacturing stage, and - measurements at official testing stations. NOTE 1 The results obtained by this method give an objective measure of the noise emitted under the specified conditions of test. It is necessary to consider the fact that the subjective appraisal of the noise annoyance of different classes of motor vehicles is not simply related to the indications of a sound measurement system. As annoyance is strongly related to personal human perception, physiological human conditions, culture, and environmental conditions, there is a large variation and it is, therefore, not useful as a parameter to describe a specific vehicle condition. NOTE 2 Spot checks of vehicles chosen at random are rarely made in an ideal acoustical environment. If measurements are carried out on the road in an acoustical environment that does not fulfil the requirements stated in this document, the results obtained can deviate appreciably from the results obtained using the specified conditions.

Acoustique — Méthode d'ingénierie pour le mesurage du bruit émis par les véhicules routiers en accélération — Partie 1: Catégories M et N

General Information

• Status: Published
• Publication Date: 20-Nov-2022
• ICS: 17.140.30 - Noise emitted by means of transport
• ICS: 43.020 - Road vehicles in general
• Technical Committee: ISO/TC 43/SC 1 - Noise
• Drafting Committee: ISO/TC 43/SC 1/WG 42 - Joint ISO/TC 43/SC 1 - ISO/TC 22 WG: Measurement of noise emission (external) from road vehicles
• Parallel Committee: ISO/TC 22 - Road vehicles
• Current Stage: 6060 - International Standard published
• Start Date: 21-Nov-2022
• Due Date: 09-Mar-2023
• Completion Date: 21-Nov-2022

Relations

• Revises: ISO 362-1:2015 - Measurement of noise emitted by accelerating road vehicles - Engineering method - Part 1: M and N categories
• Effective Date: 23-Apr-2020

Overview

ISO 362-1:2022 - Acoustics: Engineering method for measurement of noise emitted by accelerating road vehicles - Part 1: M and N categories - defines a repeatable, engineering-focused test method to measure the noise emitted by road vehicles of categories M (passenger transport) and N (goods transport) under typical urban traffic conditions. The standard is designed for simplicity and reproducibility and is intended for controlled test environments (extensive open space) used in type approval, manufacturing checks, and official test stations. It provides objective sound pressure measurements while noting that subjective human annoyance is outside its scope.

Key topics and technical requirements

• Scope and vehicle coverage: Applies to vehicle categories M and N; excludes two‑ and three‑wheelers (L1–L5) - see ISO 9645 and ISO 362‑2 for those categories.
• Test philosophy: Reproduces principal noise sources during normal urban driving by combining a wide‑open‑throttle acceleration phase and a constant‑speed phase to simulate in‑use urban conditions.
• Acceleration specification and calculation: Procedures to calculate target and reference accelerations, with different methods for manual, automatic, adaptive and CVT transmissions and treatments for locked vs non‑locked gear ratios.
• Instrumentation: Requirements for acoustical measurement systems (microphones, calibration, data acquisition), speed and meteorological instrumentation, and conformity checks.
• Acoustical environment and meteorology: Tests require a large open test site, defined meteorological conditions, and limits on background noise to ensure valid measurements.
• Microphone positions and operating conditions: Defined microphone locations, vehicle preparation (test mass, tyre selection, battery state), additional sound‑emitting devices, and cooling system controls.
• Data handling and uncertainty: Procedures for measurement readings, data compilation, reported values, and a framework for measurement uncertainty (reference to ISO/IEC Guide 98‑3).
• Annexes and tools: Informative annexes provide technical background, uncertainty analysis, and flowcharts for different vehicle categories and test modes.

Practical applications and users

• Vehicle manufacturers for type‑approval testing and production quality checks.
• Certification bodies and regulatory agencies conducting official noise compliance testing.
• Acoustic test laboratories and test stations implementing standardized vehicle noise measurement procedures.
• OEM calibration and R&D teams evaluating vehicle noise sources and mitigation measures.
• Environmental and urban planners using objective data for noise mapping and policy development.

Related standards

• ISO 9645 - two‑ and three‑wheel vehicles (L1, L2)
• ISO 362‑2 - other L categories (L3, L4, L5)
• ISO/IEC Guide 98‑3 - measurement uncertainty framework referenced in annexes

ISO 362-1:2022 is a practical, internationally recognized method for consistent measurement of accelerating vehicle noise in urban contexts, supporting regulatory compliance, product development, and objective acoustic assessment.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 362-1
Third edition
2022-11
Acoustics — Engineering method for
measurement of noise emitted by
accelerating road vehicles —
Part 1:
M and N categories
Acoustique — Méthode d'ingénierie pour le mesurage du bruit émis
par les véhicules routiers en accélération —
Partie 1: Catégories M et N
Reference number
© ISO 2022
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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Phone: [phone]
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Published in Switzerland
ii
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
3.1 Vehicle mass . 2
4 Symbols, terms and abbreviated terms . 7
5 Specification of the acceleration for vehicles of categories M1 and M2 having a
maximum authorized mass not exceeding 3 500 kg and of category N1 .10
5.1 General . 10
5.2 Calculation of acceleration . 11
5.2.1 Calculation procedure for vehicles with manual transmission, automatic
transmission, adaptive transmission, and continuously variable
transmission (CVT) tested with locked gear ratios . 11
5.2.2 Calculation procedure for vehicles with automatic transmission, adaptive
transmission, and CVT tested with non-locked gear ratios. 11
5.3 Calculation of the target acceleration .12
5.4 Calculation of the reference acceleration .12
5.5 Partial power factor k . 13
P
6 Instrumentation .13
6.1 Instruments for acoustical measurement . 13
6.1.1 General .13
6.1.2 Calibration . . .13
6.1.3 Conformity with requirements . 14
6.2 Instrumentation for speed measurements . 14
6.3 Meteorological instrumentation . 14
7 Acoustical environment, meteorological conditions, and background noise .14
7.1 Test site . 14
7.2 Meteorological conditions . 16
7.3 Background noise. 16
8 Test procedures .17
8.1 Microphone positions . 17
8.2 Conditions of the vehicle . 17
8.2.1 General conditions . 17
8.2.2 Test mass of the vehicle . 17
8.2.3 Tyre selection and condition . 22
8.2.4 Calculation of total engine power . 22
8.2.5 Battery state of charge . . .23
8.2.6 Additional sound emitting devices . 23
8.2.7 Vehicle cooling fans or cooling systems . 23
8.3 Operating conditions . 23
8.3.1 Vehicles of categories M1 and M2 having a maximum authorized mass not
exceeding 3 500 kg and category N1 . 23
8.3.2 Vehicles of category M2 having a maximum authorized mass exceeding
3 500 kg, and categories M3, N2 and N3 . 27
8.4 Measurement readings and reported values . 31
8.4.1 General . 31
8.4.2 Data compilation . 32
8.4.3 Vehicles of categories M1 and M2 having a maximum authorized mass not
exceeding 3 500 kg and category N1 . 32
iii
8.4.4 Vehicles of category M2 having a maximum authorized mass exceeding
3 500 kg and categories M3, N2, and N3 . 33
8.5 Measurement uncertainty . .33
9 Test report .34
Annex A (informative) Technical background for development of vehicle noise test
procedure based on in-use operation in urban conditions .36
Annex B (informative) Measurement uncertainty — Framework for analysis according to
ISO/IEC Guide 98-3 .56
Annex C (informative) Flowchart of the procedure for categories M1 and M2 having a
maximum authorized mass not exceeding 3 500 kg and category N1 .66
Annex D (informative) Flowchart for vehicles of category M2 having a maximum authorized
mass exceeding 3 500 kg and categories M3, N2, and N3 with locked gears .71
Annex E (informative) Flowchart for vehicles of category M2 having a maximum authorized
mass exceeding 3 500 kg and categories M3, N2, and N3 with non-locked gears .72
Annex F (informative) Flowchart for vehicles of category M2 having a maximum authorized
mass exceeding 3 500 kg and categories M3, N2, and N3 with no rotational engine
speed available .74
Bibliography .75
iv
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 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.
ISO collaborates closely 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 documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions 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 43, Acoustics, Subcommittee SC 1, Noise.
This third edition cancels and replaces the second edition (ISO 362-1:2015), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— Clarification on the measurement zone to provide equivalent results between hand held sound level
meters and digital data acquisition systems.
— Clarification of original intent of ISO 362-1 on M1/N1 gear ratio selection to account for practical
lessons learned.
— Clarification and examples of measures used to control vehicle operation so as to provide the
specified accelerations of ISO 362-1
— Addition of and clarification of tolerances, measurement precision, vehicle operation, vehicle
physical attributes, and calculation methods where multiple interpretations could be possible.
— Addition of a representative virtual vehicle for N3.
— Update to measurement uncertainty.
A list of all parts in the ISO 362 series can be found on the ISO website.
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.
v
Introduction
An extensive review was conducted of actual in-use vehicle operations, beginning with data from the
TUV Automotive study in the early 1990s and continuing with data developed through other committee
members from 1996 through 2000. It includes nearly 100 vehicles operated on a variety of urban roads
in Europe and Asia. The primary focus of the in-use measurements was to determine how vehicles
are driven with a variety of vehicles, driving behaviours, and traffic situations. The in-use behaviour
determined from these studies was successfully correlated to urban traffic use in the United States by
evaluation of the fuel economy test cycles used by the United States Environmental Protection Agency
(USEPA). The resulting test specifications are therefore valid for all global urban use conditions.
The procedure defined here provides a measure of the sound pressure level from vehicles under
controlled and repeatable conditions. The definitions have been made according to the requirements
of vehicle categories. In cases of vehicles other than very heavy trucks and buses, the working group
found that attempts to conduct a partial load test as in actual use resulted in considerable run-to-run
variability that significantly interfered with the repeatability and reproducibility of the test cycle.
Therefore, two primary operating conditions (i.e. a wide-open-throttle acceleration phase and a
constant speed phase) were used to guarantee simplicity. The combination was found to be equivalent
to the partial throttle and partial power (engine load) actually used.
As a further consequence of the investigation of the requirements for an efficient test, it was decided
to design a test which was independent of vehicle design and therefore safe and adaptable for future
technologies, as well as for future traffic conditions. The test guarantees an excitation of all relevant
noise sources, and the final test result reflects a combination of these sources as a compromise between
normal urban use and “worst case”.
In 2004, the given test for M and N category vehicles was evaluated for technical accuracy and practical
considerations by test programmes carried out by the Japan Automobile Standards Internationalization
Center (JASIC), the European Automotive Manufacturers Association (ACEA), and the Society of
Automotive Engineers, Inc. (SAE) in the United States. Over 180 vehicles were included in these tests.
The reports of these test programmes were considered prior to preparation of this document.
This document was developed following demands for a new test procedure considering the following:
— “The test procedure (ISO 362) doesn't reflect realistic driving conditions” (1996 EU Green Paper);
— “In the case of motor vehicles, other factors are also important such as the dominance of tyre noise
above quite low speeds (50 km/h)” (1996 EU Green Paper).
— “A new measurement procedure should require that the major noise sources of a vehicle be
measured” (2001 Noise Emission of Road Vehicles – I-INCE).
This document, while maintaining the same technical procedures as the previous edition, has been
revised based on practical experience to provide additional clarification where multiple interpretations
were possible, to provide additional equivalent test modes for heavy commercial vehicles, and to
incorporate provisions for addressing and including in the measurement external sound systems for
M1 and N1 category vehicles.
vi
INTERNATIONAL STANDARD ISO 362-1:2022(E)
Acoustics — Engineering method for measurement of
noise emitted by accelerating road vehicles —
Part 1:
M and N categories
1 Scope
This document specifies an engineering method for measuring the noise emitted by road vehicles of
categories M and N under typical urban traffic conditions. It excludes vehicles of category L1 and L2,
which are covered by ISO 9645, and vehicles of category L3, L4, and L5, which are covered by ISO 362-2.
The specifications are intended to reproduce the level of noise generated by the principal noise sources
during normal driving in urban traffic (see Annex A).
The method is designed to meet the requirements of simplicity as far as they are consistent with
reproducibility of results under the operating conditions of the vehicle.
The test method requires an acoustical environment that is obtained only in an extensive open space.
Such conditions are usually provided for
— type approval measurements of a vehicle,
— measurements at the manufacturing stage, and
— measurements at official testing stations.
NOTE 1 The results obtained by this method give an objective measure of the noise emitted under the specified
conditions of test. It is necessary to consider the fact that the subjective appraisal of the noise annoyance of
different classes of motor vehicles is not simply related to the indications of a sound measurement system. As
annoyance is strongly related to personal human perception, physiological human conditions, culture, and
environmental conditions, there is a large variation and it is, therefore, not useful as a parameter to describe a
specific vehicle condition.
NOTE 2 Spot checks of vehicles chosen at random are rarely made in an ideal acoustical environment. If
measurements are carried out on the road in an acoustical environment that does not fulfil the requirements
stated in this document, the results obtained can deviate appreciably from the results obtained using the
specified conditions.
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 362-3, Acoustics – Measurement of noise emitted by accelerating road vehicles – Engineering method,
Part 3: Indoor testing M and N categories
ISO 1176, Road vehicles — Masses — Vocabulary and codes
ISO 2416, Passenger cars — Mass distribution
ISO 10844, Acoustics — Specification of test tracks for measuring sound emitted by road vehicles and their
tyres
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
me a s ur ement (GUM: 1995)
IEC 60942, Electroacoustics — Sound calibrators
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1176 and ISO 2416 and the
following apply.
ISO and IEC maintain terminological 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 Vehicle mass
3.1.1
kerb mass
complete shipping mass of a vehicle fitted with all standard equipment necessary for normal operation
plus the mass of the following elements for M1, N1, and M2 having a maximum authorized mass not
exceeding 3 500 kg:
— lubricants, coolant (if needed), washer fluid;
— fuel (tank filled to at least 90 % of the capacity specified by the manufacturer);
— other equipment if included as basic parts for the vehicle, such as spare wheel(s), wheel chocks, fire
extinguisher(s), spare parts, and tool kit
Note 1 to entry: The definition of kerb mass can vary from country to country, but in this part of ISO 362, it refers
to the definition contained in ISO 1176.
[SOURCE: ISO 1176:1990, 4.4 and 4.6 — modified.]
3.1.2
maximum authorized mass
kerb mass (3.1.1) plus the maximum allowable payload
3.1.3
unladen vehicle mass
nominal mass of a complete N2, N3, or M2 vehicle having a maximum authorized mass (3.1.2) greater
than 3 500 kg or an M3 vehicle as determined by the following conditions:
a) mass of the vehicle includes the bodywork and all factory-fitted equipment and electrical and
auxiliary equipment for normal operation of the vehicle, including liquids, tools, fire extinguisher,
standard spare parts, chocks, and spare wheel, if fitted;
b) the fuel tank is filled to at least 90 % of rated capacity and the other liquid-containing systems
(except those for used water) are filled to 100 % of the capacity specified by the manufacturer
3.1.4
mass of the driver
nominal mass of a driver
3.1.5
mass in running order
nominal mass of a vehicle as determined by the following conditions:
a) the mass is taken as the sum of the unladen vehicle mass (3.1.3) and the driver's mass;
b) in the case of category M2 and M3 vehicles that include seating positions for additional
crewmembers, their mass is incorporated in the same way and equal to that of the driver
c) mass in running order mathematically rounded, reported, and used for calculations to a precision
of 10 kg (xxxx0)
Note 1 to entry: The driver's mass is calculated in accordance with ISO 2416.
3.1.6
maximum axle (group of axles) capacity
permissible mass corresponding to the maximum mass that can be carried by the axle (group of axles)
as defined by the vehicle manufacturer, not exceeding the axle manufacturer's specifications
3.1.7
unladen axle load
actual mass carried by the axle (or group of axles) in an unladen condition, either in the front or the
rear of the vehicle
Note 1 to entry: The unladen vehicle mass is equal to the sum of the unladen axles (or group of axles) load.
3.1.8
extra loading
mass which is added to the unladen vehicle mass (3.1.3)
3.1.9
laden axle load
actual mass carried by the axle (or group of axles) in a laden condition, either in the front or the rear of
the vehicle
3.2
power-to-mass ratio index
PMR
dimensionless quantity used for the calculation of acceleration according to the following formula:
P
n
PMR = ⋅1 000
m
ro
where
P is the numerical value of total engine power, expressed in kilowatts;
n
m is the numerical value of the mass in running order, expressed in kilograms;
ro
3.2.1
total engine power
sum of all power from available propulsion sources
3.3
rated engine speed
S
engine speed at which the combustion engine develops its rated maximum net power as stated by the
manufacturer
Note 1 to entry: If the rated maximum net power is reached at several engine speeds, S used in this document is
the highest engine speed at which the rated maximum net power is reached.
Note 2 to entry: ISO 80000-3 defines this term as “rated engine rotational frequency”. The term “rated engine
speed” was retained due to its common understanding by practitioners and its use in government regulations.
3.4 Vehicle categories
3.4.1
category L
motor vehicles with fewer than four wheels
Note 1 to entry: United Nations Economic Commission for Europe (UNECE) document TRANS/WP.29/78/Rev.1/
Amend.4 (26 April 2005) extended the L category to four-wheeled vehicles as defined by L6 and L7.
3.4.1.1
category L1 and L2
mopeds
Note 1 to entry: See ISO 9645 for further details.
3.4.1.2
category L3
two-wheeled motor vehicles with an engine cylinder capacity greater than 50 cm or maximum speed
greater than 50 km/h
3.4.1.3
category L4
three-wheeled motor vehicles with an engine cylinder capacity greater than 50 cm or maximum speed
greater than 50 km/h, the wheels being attached asymmetrically along the longitudinal vehicle axis
3.4.1.4
category L5
three-wheeled motor vehicles with an engine cylinder capacity greater than 50 cm or maximum speed
greater than 50 km/h, having a gross vehicle mass rating not exceeding 1 000 kg and wheels attached
symmetrically along the longitudinal vehicle axis
3.4.1.5
category L6
four-wheeled vehicles whose unladen mass is not more than 350 kg, not including the mass of the
batteries in the case of electric vehicles, whose maximum design speed is not more than 45 km/h and
whose engine cylinder capacity does not exceed 50 cm for spark (positive) ignition engines, or whose
maximum net power output does not exceed 4 kW in the case of other internal combustion engines, or
whose maximum continuous rated power does not exceed 4 kW in the case of electric engines
3.4.1.6
category L7
four-wheeled vehicles, other than those classified as category L6 (3.4.1.5), whose unladen mass is not
more than 400 kg or 550 kg for vehicles intended for carrying goods, not including the mass of the
batteries in the case of electric vehicles, and whose maximum continuous rated power does not exceed
15 kW
3.4.2
category M
power-driven vehicles having at least four wheels and used for the carriage of passengers
3.4.2.1
category M1
vehicles used for the carriage of passengers and comprising no more than eight seats in addition to the
driver's seat
3.4.2.2
category M2
vehicles used for the carriage of passengers and comprising more than eight seats in addition to the
driver's seat and having a maximum mass not exceeding 5 000 kg
Note 1 to entry: In this definition, “maximum mass” is equivalent to “maximum authorized mass” used elsewhere
in this document.
3.4.2.3
category M3
vehicles used for the carriage of passengers and comprising more than eight seats in addition to the
driver's seat and having a maximum mass exceeding 5 000 kg
Note 1 to entry: In this definition, “maximum mass” is equivalent to “maximum authorized mass” used elsewhere
in this document.
3.4.2.4
incomplete vehicle of category M2 or M3
incomplete vehicle with just chassis rails or tube assembly, power train, and axles, which is intended to
be completed with bodywork, customized to the needs of the transport operator
3.4.3
category N
power-driven vehicles having at least four wheels and used for the carriage of goods
3.4.3.1
category N1
vehicles used for the carriage of goods and having a maximum authorized mass (3.1.2) not exceeding
3 500 kg
3.4.3.2
category N2
vehicles used for the carriage of goods and having a maximum authorized mass (3.1.2) exceeding
3 500 kg but not exceeding 12 000 kg
3.4.3.3
category N3
vehicles used for the carriage of goods and having a maximum authorized mass (3.1.2) exceeding
12 000 kg
3.5
reference point
point depending on the design and category of the vehicle
— for category M1 and N1 vehicles and M2 having a maximum authorized mass not exceeding 3 500 kg
point on the vehicle as follows:
— for front-engine vehicles, the front end of the vehicle;
— for mid-engine vehicles, the centre of the vehicle;
— for rear-engine vehicles, the rear end of the vehicle
Note 1 to entry: For vehicles having multiple propulsion sources, the reference point is determined by the position
of the propulsion source having the highest power. If there are multiple propulsion sources of equivalent power,
then the position of the most forward propulsion source shall prevail.

— for category M2 having a maximum authorized mass exceeding 3 500 kg, M3, N2, and N3 vehicles
point on the vehicle as follows:
— for front-engine vehicles, the front end of the vehicle;
— for all other vehicles, the border of the engine closest to the front of the vehicle
3.6
target acceleration
acceleration at a partial throttle condition in urban traffic, derived from statistical investigations
Note 1 to entry: Refer to Annex A for more detailed explanations.
3.7
reference acceleration
required acceleration during the acceleration test on the test track
Note 1 to entry: Refer to Annex A for more detailed explanations.
3.8
gear ratio weighting factor
k
dimensionless quantity used to combine the test results of two gear ratios for the acceleration test and
the constant-speed test
3.9
partial power factor
k
P
dimensionless quantity used for the weighted combination of the test results of the acceleration test
and the constant-speed test for vehicles of categories M1, N1, and M2 having a maximum authorized
mass (3.1.2) not exceeding 3 500 kg
Note 1 to entry: Refer to Annex A for more detailed explanations.
3.10
pre-acceleration
application of acceleration control device prior to the position AA' for the purpose of achieving stable
acceleration between AA' and BB'
Note 1 to entry: See Figure 1 for additional details.
3.11
locked gear ratio
control of transmission such that the transmission gear cannot change during a test
3.12
engine
power source without detachable accessories
Note 1 to entry: power source includes in this context all sources of motive power; for example, electric or
hydraulic power sources used alone or in combination with other power sources.
3.13
test track length
l
length of test track used in the calculation of acceleration from points PP' to BB'
3.14
test track length
l
length of test track used in the calculation of acceleration from points AA' to BB'
3.15
target engine rotational speed
n
target BB’
interval between 70 % and 74 % of the speed S for vehicles of category M2 having a maximum authorized
mass (3.1.2) exceeding 3 500 kg and N2 and an interval between 85 % and 89 % of the speed S for
vehicles of category M3 and N3
3.16
target vehicle speed
v
target BB’
vehicle speed of 35 km/h ± 5 km/h
3.17
kickdown
driver activated automated gearshift to a test condition outside the target conditions
Note 1 to entry: The target conditions are defined in this document.
3.18
prevention of downshift
measure by the vehicle manufacturer to ensure that the vehicle is tested within its specific target
conditions
3.19
stable acceleration
acceleration which avoids unsteady accelerations such as lugging, jerking, hesitation, delays, or other
similar effects. When acceleration is calculated as part of the measurement, stable acceleration means a
consistent acceleration over the complete measurement distance between AA' and BB' plus the vehicle
length.
3.20
exterior sound enhancement system
any system installed on the vehicle for producing sound
Note 1 to entry: Exterior sound enhancement systems may be integrated into other components, such as the
exhaust, or may be independent units.
4 Symbols, terms and abbreviated terms
Table 1 lists the symbols, terms, and abbreviated terms used in this document and the subclause where
they are used for the first time.
Table 1 — Symbols and abbreviated terms used and corresponding clauses
Symbol Unit Subclause Explanation
AA' — 3.10 Line perpendicular to vehicle travel which indicates beginning of
zone in which to record sound pressure level during test
a m/s A.2.6 Partial throttle acceleration in gear ratio I; value to be reported and
i
used for calculations to the second decimal place (x,xx)
a m/s A.2.2.3 Maximum acceleration during an acceleration phase measured in
max
in-use studies
2 th
a m/s A.2.3.1 90 percentile of maximum acceleration during an acceleration
max,90
phase measured in in-use studies
a m/s A.2.2.1 In-use acceleration measured in urban traffic for a specific vehicle
acc
2 th
a m/s A.2.8.1 Acceleration at 90 percentile of noise emission and 50 km/h vehi-
acc,50
cle velocity for a specific vehicle
a m/s 5.1 Acceleration in gear ratio I; value to be reported and used for calcu-
acc,i
lations to the second decimal place (x,xx)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Unit Subclause Explanation
a m/s 5.1 Acceleration in gear ratio (i + 1); value to be reported and used for
acc (i + 1)
calculations to the second decimal place (x,xx)
a m/s 5.1 Acceleration in single gear ratio test cases; value to be reported and
acc,test
used for calculations to the second decimal place (x,xx)
a m/s 5.4 Reference acceleration for the acceleration test; value to be report-
acc,ref
ed and used for calculations to the second decimal place (x,xx)
a m/s 5.3 Target acceleration representing urban traffic acceleration; value to
urban
be reported and used for calculations to the second decimal place
(x,xx)
BB' — 3.10 Line perpendicular to vehicle travel which indicates end of zone in
which is 10,00 m behind line PP'
CC' — 8.1 Centre line of vehicle travel through test surface as defined in
ISO 10844
δ − δ dB B.2 Input quantities to allow for any uncertainty
1 7
gear ratio i — 8.3.1.3.2 Gear ratio which provides an acceleration within the 5 percent
tolerance of the reference acceleration a or greater than the
acc,ref
reference acceleration a
acc,ref
gear ratio (i + 1) — 8.3.1.3.2 The second of two gear ratios, with an acceleration lower than gear
ratio i
gear ratio i+2, 8.3.1.3.2 Gear ratios selectable, if gear ratio i and gear ratio i + 1 exceed an
i+3, … acceleration of 2,0 m/s
gear x — 8.3.2.3.2 First of two gear ratios used for testing of M2 having a maximum
authorized mass of more than 3 500 kg, M3, N2, and N3 where cer-
tain criteria on test conditions are met
gear y — 8.3.2.3.2 Second of two gear ratios used for testing of M2 having a maximum
authorized mass of more than 3 500 kg, M3, N2, and N3 where cer-
tain criteria on test conditions are met
j — 5.2.1 Index for single test run within overall acceleration or constant
speed test series i or (i + 1)
k — 3.9 Partial power factor; value to be reported and used for calculations
P
to the second decimal place (x,xx)
k — 3.8 Gear ratio weighting factor; value to be reported and used for calcu-
lations to the second decimal place
k — A.2.8.1 Interpolation factor between gears
n
l m 5.1 Reference length
ref
l m 5.1 Length of vehicle; value to be reported and used for calculations to a
veh
precision of 0,01 m (1 cm)
l m 3.13 Length of test section for calculation of acceleration from PP' to BB'
l m 3.14 Length of test section for calculation of acceleration from AA' to BB'
L dB 8.4.3.2 Vehicle sound pressure level at constant speed test for gear i; value
crs,i
to be reported and used for calculations to the first decimal place
(xx,x)
L dB 8.4.3.2 Vehicle sound pressure level at constant speed test for gear (i + 1);
crs (i + 1)
value to be reported and used for calculations to the first decimal
place (xx,x)
L dB 8.4.3.2 Reported vehicle sound pressure level at constant speed test; value
crs,rep
to be reported and used for calculations to the first decimal place
(xx,x)
L dB 8.4.3.2 Vehicle sound pressure level at acceleration test for gear i; value
acc,i
to be reported and used for calculations to the first decimal place
(xx,x)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Unit Subclause Explanation
L dB 8.4.3.2 Vehicle sound pressure level at acceleration test for gear (i + 1);
acc (i + 1)
value to be reported and used for calculations to the first decimal
place (xx,x)
L dB 8.4.3.2 Reported vehicle sound pressure level at acceleration; value to be
acc,rep
reported and used for calculations to the first decimal place (xx,x)
L dB 8.4.3.2 Reported vehicle sound pressure level representing urban opera-
urban
tion; value to be reported mathematically rounded to the nearest
integer (xx)
m kg 8.2.2.1 Maximum rear axle capacity
ac,ra,max
m kg 8.2.2.2.4 Technically permissible maximum laden mass allowed for the cho-
ac,ra,max (chosen)
sen rear axle (as defined in 8.2.2.2.4)
m kg 8.2.2.1 Mass of the incomplete vehicle (M2 or M3)
chassisM2M3
m kg 8.2.2.1 Mass of the driver
d
m kg 8.2.2.2.2 Laden front axle load
fa,load,laden
m kg 8.2.2.1 Unladen front axle load
fa,load,unladen
m kg 8.2.2.2.4 Measured unladen front axle load of the virtual vehicle with more
fa,(vrf),load,unladen
than two axles
m kg 8.2.2.2.2 Laden rear axle load
ra,load,laden
m kg 8.2.2.1 Unladen rear axle load
ra,load,unladen
m kg 8.2.2.1 Mass in running order
ro
M kg 3.2 Test mass of the vehicle
t
m kg 8.2.2.2.4 Test mass of a virtual vehicle with two axles (4×2 or 4×4)
t (2 axles virtual)
m kg 8.2.2.1 Target mass of the vehicle
target
m kg 8.2.2.1 Unladen vehicle mass
unladen
m kg 8.2.2.2.4 Unladen vehicle mass of the virtual vehicle with two axles
unladen (2 axles
virtual)
m kg 8.2.2.1 Extra loading
xload
m kg 8.2.2.2.4 Extra loading for the virtual vehicle with two axles
xload (2 axles
virtual)
m kg 8.2.2.1 Extra load to be added to the incomplete vehicle (M2 or M3) to
xloadM2M3
reach the mass of the vehicle in running order as chosen by the
manufacturer
n — 8.3.1.3.2 Gear index number (see Note 3)
n 1/min A.2.4 Engine rotational speed of the vehicle
n 1/min 9 Engine rotational speed of the vehicle when the reference point
PP'
passes PP'; value to be reported and used for calculations to a preci-
-1
sion of 10 min (xxx0)
n 1/min 8.3.2.1 Engine rotational speed of the vehicle when the reference point
BB'
passes BB'; value to be reported and used for calculations to a preci-
-1
sion of 10 min (xxx0)
n , i=1,2 1/min 8.3.2.3.3 engine rotational speed when the reference point passes BB' when
BB'i
certain conditions are met
n 1/min 8.3.1.3.2 Maximum engine rotational speed permitted for M1, N1, and M2
max'
less than 3 500 kg; value to be reported and used for calculations to
-1
a precision of 10 min (xxx0)
n 1/min 8.3.2.2 Target engine rotational speed of the vehicle when the reference
target BB’
point has to pass line BB’ (see 5.1 for definition of reference point)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Unit Subclause Explanation
th
(n/S) — A.2.8.1 Dimensionless engine rotational speed ratio at 90 percentile
a 90
acceleration
th
(n/S) — A.2.6 Dimensionless engine rotational speed ratio at 90 percentile noise
L 90
emission
(n/S) — A.2.8.1 Dimensionless engine rotational speed ratio at maximum accelera-
i
tion of i gear
(n/S) — A.2.8.1 Dimensionless engine rotational speed ratio at maximum accelera-
(i + 1)
tion of (i + 1) gear
PMR — 3.2 Power-to-mass ratio index to be used for calculations (abbrevi-
ation); value to be reported and used for calculations to the first
decimal place (xxx,x)
P kW 3.2 Rated total engine power (see ISO 1585 for combustion engines)
n
PP' — 3.13 Line perpendicular to vehicle travel that indicates location of micro-
phones
S 1/min 3.3 Rated engine rotational speed in revolutions per minute, synony-
mous with the engine rotational speed at maximum power
v km/h 5.1 Vehicle velocity when reference point passes line AA' (see 5.1 for
AA'
definition of reference point); value to be reported and used for
calculations to the first decimal place
v km/h 5.1 Vehicle velocity when reference point or reference length passes
BB'
line BB' (see 5.1 for definition of reference length and see 3.5 for
definition of reference point); value to be reported and used for
calculations to the first decimal place
v km/h 8.3.2.3.3 Target vehicle velocity when certain conditions are met
BB’1
v km/h 8.3.2.3.3 Target vehicle velocity when certain conditions are met
BB’2
v km/h 5.1 Vehicle velocity when reference point passes line PP' (see 5.1 for
PP'
definition of reference point); value to be reported and used for
calculations to the first decimal place
v km/h 8.3.2.2 Target vehicle velocity when it is necessary that the reference point
target BB’
pass line BB’ (see 5.1 for definition of reference point)
v km/h 8.3.1.2 Target vehicle test velocity
test
th
v km/h A.2.3.1 50 percentile vehicle velocity at maximum acceleration during an
a,max 50
acceleration phase measured in in-use studies
th
v km/h A.2.3.1 90 percentile vehicle velocity at maximum acceleration during an
a,max 90
acceleration phase measured in in-use studies
vrf — 8.2.2.2.4 Vehicle with more than two axles representing the vehicle family
5 Specification of the acceleration for vehicles of categories M1 and M2 having a
maximum authorized mass not exceeding 3 500 kg and of category N1
5.1 General
All accelerations are calculated using different speeds of the vehicle on the test track. The formulae
given in 5.2 are used for the calculation of a , a and a . The speed either at AA' (v ) or
acc,i acc (i + 1), acc,test AA'
PP' (v ) is defined by the vehicle speed when the reference point passes AA' or PP'. The speed at BB'
PP'
(v ) is defined when the rear of the vehicle passes BB' or the front of the vehicle passes BB’ + 5 m if
BB′
l is chosen as 5 m. The method used for determination of the acceleration shall be indicated in the test
ref
report
Due to the definition of the reference point for the vehicle, the length of the vehicle is considered to be
different in Formulae (1) and (2). If the reference point is the front of the vehicle, l = l , i.e. the length
ref veh
of vehicle; if the reference point is the midpoint of the vehicle, l = 0,5 l (i.e. 0,5 times the length of
ref veh
vehicle); if the reference point is the rear of the vehicle, l = 0.
ref
At the choice of the vehicle manufacturer, front engine vehicles may use l = 5 m, and mid engine
ref
vehicles may use l = 2,5 m
ref
The dimensi
...