[WapCar] The departure angle is the angle measured between a line tangent of the rear tire and the initial point of structural interference rearward of the rear tire to ground, when the vehicle is stationary and fully loaded. Any rigid component fixed on the vehicle shouldn't be lower than this tangent line.
The departure angle applies when going downhills. When the front wheels of the vehicle approach at level ground and the rear wheels are still on the slope, the departure angle guarantees the rear bumper or other strutural components not to be stuck on the slope. The larger the departure angle is, the steeper the slopes a vehicle can move down, without damaging the rear bumper.
The Measurement of the Departure Angle
When a vehicle is stationary and fully loaded on a level ground, the maximum acute angle between the level ground and the tangent line of the rear tire below any strutural component rearwards. Notice that some models may have adjustable ride heights, hence the departure angle is variable with these models.