SAE J2971â„¢ MAR2026 establishes a common naming convention and definitions for aerodynamic devices and technologies used to control aerodynamic forces on trucks and buses weighing more than 10,000 pounds, including trailers. The Recommended Practice covers truck, tractor, bus, trailer, tire, wheel, undercarriage, and general aerodynamic devices, along with active and passive flow control systems and broader aerodynamic design concepts.
This revision updates selected definition names and Appendix A. It supports consistent terminology in technical data, reports, testing procedures, engineering documentation, and related SAE Recommended Practices, including SAE J1321, SAE J1526, SAE J1252, and SAE J2966.
Application Scope: Heavy-duty trucks, tractors, trailers, buses, aerodynamic component design, vehicle testing, fuel economy assessment, regulatory work, transportation research, and technical documentation.
