This document establishes minimum performance criteria at GCWR and calculation methodology to determine tow-vehicle TWR for passenger cars, multipurpose passenger vehicles and trucks. This includes all vehicles up to 13 000 lb GVWR. It is recommended that the performance requirements within be adopted for all vehicles with model year designation 2013 or later.
This document establishes tow-vehicle performance requirements for combination vehicle acceleration, gradeability, understeer, trailer sway response, braking and park brake at GCWR, and tow-vehicle hitch/attachment structure at TWR. In order to minimize test variations, it provides standard test trailer specifications and requirements for use in these tests. It is acknowledged that there are a wide variety of conditions experienced while trailering which cannot be completely addressed within this document and in no way is this document intended to establish or limit manufacturers' designs or instructions to the customer. This document provides simple equations to determine TWR from GCWR in conjunction with other vehicle ratings and defined vehicle weight conditions and dimensions.
