本SAE推荐实施规程定义了一套机动车尺寸的测量和标准程序。尺寸主要用于测量设计环境（即CAD）中车辆的设计意图。本实践中的所有尺寸都可以通过这种方式测量。此外，一些尺寸可以在实际车辆上测量。如果对物理性质进行测量，则应预计数值存在一些差异。此外，应注意不要将设计意图测量与物理属性测量混淆。本实施规程中描述的尺寸和程序适用于SAE J826中描述的HPM和SAE J4002中描述的HPM-II。在某些情况下，这些数字可能只反映其中之一。 除非另有规定，否则所有尺寸的测量均垂直于三维参考系统（见SAE J182），但与地面相关的尺寸除外，其定义为垂直于地面。除非另有规定，否则所有尺寸均在车辆处于整备重量时测量。所有尺寸均在基础车辆上测量，不包括常规生产选装件（RPO）或配件，除非另有规定。尽管许多术语和尺寸在名称中使用人体部位，但它们不应被解释为表明乘员舒适度、能力或舒适度的度量。

This SAE Recommended Practice defines a set of measurements and standard procedures for motor vehicle dimensions. The dimensions are primarily intended to measure the design intent of a vehicle within a design environment (i.e., CAD). All dimensions in this practice can be measured this way.In addition, some dimensions can be taken in an actual vehicle. If measurements are taken on physical properties, some differences in values should be expected. Also, care should be taken to not confuse design intent measurements with those taken on a physical property. It is intended that the dimensions and procedures described in this practice be generic in their application to both the HPM, described in SAE J826, and the HPM-II, described in SAE J4002. In some circumstances, the figures may only reflect one or the other.Unless otherwise specified, all dimensions are measured normal to the three-dimensional reference system (see SAE J182), except ground-related dimensions, which are defined normal to ground. All dimensions are taken with the vehicle at curb weight unless otherwise specified. All dimensions are measured on the base vehicle and do not include Regular Production Options (RPO) or accessory parts, unless otherwise specified.Although many terms and dimensions use human body parts in their name, they should not be construed as measures that indicate occupant accommodation, capabilities, or comfort.