GB/T 23335-2025Natural gas vehicles - Engineering approval evaluation programme (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. This document replaces GB/T 23335-2009 "Test Procedure for Type Approval of Natural Gas Vehicles". Compared with GB/T 23335-2009, except for the structure... Aside from adjustments and editorial changes, the main technical changes are as follows:

a) The file range has been changed (see Chapter 1, Chapter 1 of the.2009 edition);

b) A new chapter on "Terms and Definitions" has been added (see Chapter 3);

c) The "Test Conditions and Test Termination Conditions" have been changed (see Chapter 4, Chapter 3 of the.2009 edition);

d) The "Parameter Measurement" section has been modified, specifying the items for measuring major dimensional parameters and mass parameters, and adding measurement of the center of mass position. Requirements for measuring mobility parameters (see 5.1,

4.1 in the.2009 edition);

e) The term "Special Equipment Inspection" has been changed to "Fuel Supply System Inspection" (see 5.2,

4.2 of the.2009 edition);

f) The description of "Technical Condition Inspection" in the fuel supply system inspection has been changed (see 5.2.1,

4.2.1 in the.2009 version);

g) The test method for "Installation Requirements Inspection" in the fuel supply system inspection has been changed (see 5.2.2,

4.2.2 in the.2009 version);

h) A test item for "odometer and speedometer calibration" has been added (see 5.4);

1 Scope

GB/T 23335-2025 is the Chinese national standard covering the type approval programme for a CNG or LNG vehicle - the tests on the fuel system and its tightness, the performance and emissions on gas, the safety in collision and fire, and the sequence in which the whole vehicle is signed off. Issued on 31 October 2025, it has been in force since 1 May 2026, replacing GB/T 23335-2009.

This document specifies the requirements, test items and methods, and test report content for the type approval test of natural gas vehicles. This document applies to the installation of vehicle natural gas systems or the conversion of existing natural gas fuel systems in newly developed basic natural gas vehicles and existing model vehicles. Natural gas vehicles powered by natural gas engines.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB 1495 Limits and Measurement Methods for Exterior Noise of Automobiles During Acceleration

GB 1589 Limits for the overall dimensions, axle load and mass of automobiles, trailers and automobile combinations

GB 3847 Emission Limits and Measurement Methods for Pollutants from Diesel Vehicles (Free Acceleration Method and Loaded Deceleration Method)

GB/T 6323 Test Method for Handling Stability of Automobiles

GB 7258 Technical Conditions for Safe Operation of Motor Vehicles

GB/T 12534 General Rules for Road Test Methods of Automobiles

GB/T 12535 Test Method for Starting Performance of Automobiles

GB/T 12536 Test Method for Coasting of Automobiles

GB/T 12538 Determination of the position of the center of gravity of road vehicles

GB/T 12539 Test Method for Automobile Climbing Steep Hills

GB/T 12540 Methods for measuring minimum turning diameter, turning circle and overrun of automobiles and automobile trains

GB/T 12543 Test Methods for Acceleration Performance of Automobiles

GB/T 12544 Test Method for Maximum Vehicle Speed