ISO 8855:2011

Overview

ISO 8855:2011 - Road vehicles: Vehicle dynamics and road‑holding ability - Vocabulary provides a standardized vocabulary of principal terms used in vehicle dynamics. The second edition (2011) updates and harmonizes earlier terminology (ISO 8855:1991) with comparable guidance such as SAE J670, and extends scope to cover tyre/wheel axis systems, inclined or non‑uniform road surfaces, multi‑unit vehicle combinations, and four‑wheel steer geometries. The vocabulary applies to passenger cars, buses and commercial vehicles with one or more steered axles.

Key topics

This vocabulary standard defines clear, unambiguous terms across the full span of vehicle dynamics and road‑holding ability. Major technical topics include:

• Axis and coordinate systems: earth‑fixed, vehicle, intermediate, tyre and wheel axis/coordinate systems, road plane definitions.
• Vehicle geometry and masses: vehicle reference point, sprung mass, wheel/tyre geometry.
• Motion variables: linear and angular motion variables, trajectory measures.
• Forces and moments: nomenclature for forces and moments acting on vehicle and tyres.
• Suspension and steering geometry: steer, camber and steering‑axis geometry terms.
• Kinematics and compliances: wheel kinematics, suspension compliance terminology.
• Ride and roll stiffness: terminology relating to vertical and roll response.
• Tyre terms: tyre geometry, tyre forces and moments, contact patch and related measures.
• Input types, control modes and responses: definitions for test inputs, control strategies, stability, understeer/oversteer measures and lateral response metrics.
• Annexes and index: informative commentary and bibliography to support interpretation.

Applications

ISO 8855:2011 is a reference for consistent terminology in:

• Vehicle dynamics design and simulation (model naming, parameter exchange).
• Test procedures and reporting for handling, stability and ride tests.
• Technical specifications, cross‑supplier communication and procurement documents.
• Academic research, textbooks and training materials (permitted reproduction rules apply).
• Regulatory or harmonization work where precise definitions of terms (e.g., understeer/oversteer measures, tyre axis systems) are required.

Who uses this standard

Typical users include:

• OEM vehicle dynamics, chassis and suspension engineers
• Simulation and CAE teams creating multi‑body or tyre models
• Test engineers and certification laboratories
• Tier‑1 suppliers (tyres, steering, suspension components)
• Researchers, educators and standards organizations

Related standards

• SAE J670 (vehicle dynamics vocabulary) - harmonization target cited in ISO 8855:2011
• ISO 8855:1991 - original edition superseded by the 2011 revision

Keywords: ISO 8855:2011, vehicle dynamics vocabulary, road‑holding ability, axis system, tyre axis system, vehicle axis system, understeer, oversteer, road vehicles.