SAE J2908-2023 PDF

Full title and description

SAE J2908-2023 — "Vehicle Power and Rated System Power Test for Electrified Powertrains". An SAE Information Report that defines test methods, data post-processing and reporting procedures to determine maximum wheel power and a comparable "rated system power" for vehicles with electrified powertrains (BEV, HEV, PHEV, FCEV) and light/medium-duty commercial vehicles.

Abstract

This information report provides a flexible, reproducible framework to measure peak wheel power and to derive a rated system power that can be compared with traditional engine power ratings. It describes test configurations (chassis, wheel or hub dynamometers), vehicle and laboratory conditioning, data acquisition and post-processing rules needed to report consistent system-power numbers across diverse electrified architectures. The document aims to reduce variability in published power figures and to make EV/ hybrid power ratings more comparable with ICE ratings.

General information

• Status: Published / Active (revises SAE J2908:2017).
• Publication date: January 17, 2023 (edition 2023).
• Publisher: SAE International (Society of Automotive Engineers).
• ICS / categories: Automotive / Electrified road vehicles; commonly associated ICS headings used for related EV and E/E standards include 43.120 (electric road vehicles) and 43.040.x (road‑vehicle electrical/electronic equipment).
• Edition / version: SAE J2908:2023 (revision of SAE J2908:2017).
• Number of pages: 27 pages (PDF / print).

Scope

Applies to passenger cars and light- and medium-duty vehicles (GVW < 10,000 lb) with electrified powertrains (battery, hybrid, plug‑in hybrid, fuel‑cell). The report covers test methods to evaluate maximum wheel power and a procedure to convert measured wheel power into a rated system power comparable with traditional engine/motor power ratings (e.g., SAE J1349, UN ECE R85). Tests may be conducted on chassis, wheel or hub dynamometers and include options to incorporate bench/ component test data.

Key topics and requirements

• Definitions: SAE system power and distinction between wheel power (measured) and rated system power (derived).
• Test equipment: permitted use of chassis, wheel‑hub or hub dynamometers and required dynamometer calibration/conditioning procedures.
• Vehicle preconditioning: batterie state‑of‑charge (SoC) limits, thermal conditioning and cooling system settings to ensure repeatable power measurements.
• Power timing windows: procedures to record short impulse (sub‑2 s) and sustained power intervals (e.g., 8–10 s) and rules to treat boost/temporary modes.
• Data acquisition and post‑processing: filtering, averaging, drivetrain loss treatment and algorithms to report SAE rated system power.
• Applicability notes: guidance on adapting the methods to multi‑motor or complex hybrid architectures and on when bench data may substitute for direct vehicle tests.

Typical use and users

Used by OEM powertrain and vehicle test engineers, independent testing laboratories, certification bodies, automotive technical publications and regulators who need a reproducible, comparable metric of vehicle propulsion power for electrified architectures. Also useful to consumer labs and marketing teams that need defensible power claims.

Related standards

References and related documents include SAE J1349 (engine net power methodology), UN ECE R85 (electric machine power/rated power definitions), ISO/IEC standards for dynamometer and electrical‑equipment testing, and national adaptations such as GB/T methods for powertrain power measurement. J2908 is positioned to align reporting of EV/hybrid power with these existing frameworks.

Keywords

electrified powertrain, wheel power, rated system power, SAE J2908, dynamometer test, BEV, PHEV, HEV, FCEV, power rating, power measurement

FAQ

Q: What is this standard?

A: SAE J2908:2023 is an SAE Information Report that specifies methods to measure maximum wheel power and to determine a comparable rated system power for vehicles with electrified powertrains.

Q: What does it cover?

A: It covers test setups (chassis/wheel/hub dynamometers), vehicle and laboratory conditioning, data capture and post‑processing methods, and rules for reporting short‑duration (impulse) and sustained power as well as deriving a rated system power comparable to conventional engine ratings.

Q: Who typically uses it?

A: Vehicle and powertrain test engineers, independent test laboratories, OEM validation teams, regulators and technical media — any organization needing repeatable, comparable power ratings for electrified vehicles.

Q: Is it current or superseded?

A: The 2023 edition (SAE J2908:2023) is a revision of SAE J2908:2017; it is published and in active use. Users should check SAE International for any later amendments or corrigenda.

Q: Is it part of a series?

A: J2908 is an SAE technical report within SAE’s ground‑vehicle/testing family and is complementary to other SAE and international standards addressing engine/motor power (e.g., SAE J1349), dynamometer testing and EV component testing. It is intended to align EV/hybrid power reporting with established power‑rating standards.

Q: What are the key keywords?

A: Wheel power, rated system power, electrified powertrain, dynamometer, BEV, HEV, PHEV, FCEV, power rating, SAE J2908.