Ahh, okay. The test is to drive up a ramp with one front tire, until another tire lifts (usually the rear tire on the same side as the one going up the ramp). Then you do a quick calculation to get the
Ramp Travel Index (RTI) score. This is an objective measure of articulation, and it tells you how much flex you can get out of the suspension before you lift a tire. The test will involve stuffing two of the tires up into the wheel well. This is not meant to be how you drive all the time, but it tells you what it is capable of handling before maxing out. In practice, vehicles with lots of suspension travel are capable of traversing very technical terrain, but - perhaps more importantly - in moderate technical terrain the body of the vehicle stays flat, while the four wheels go up and down. The ride is comfortable because the body is staying relatively level, and the suspension is doing all the work. Its also safer having all four tires in contact with the ground.
For a better explanation, check out this video from Scott Brady at Expedition Portal (the same guy who recently did an excellent
review of the Grenadier). He is reviewing a Wrangler modified by AEV, but the point is it has been modified in a way that increases the characteristics I am describing above. In the first part of the video they take the Jeep to the race track, which might seem silly, but testing its max track performance gives an idea of how it will handle on-road (even though normal folk won't push it as hard on a public road). In addition, they take it to the track to demonstrate that a lifted vehicle on 35s does not have to drive worse on road that a stock vehicle; when done right, it can drive better. But in the second part of the video (around the 3:30 mark) they drive off road (also on with an AEV vehicle, but this one on 37s). Watch how flat the hood remains while the suspension articulates around 3:40 in the video. So the point of having a really good RTI score is not to always be stuffing your tires up into the wheel well, but understanding the type of terrain you can traverse safely and comfortably.