About the diffuculty levels: There are five categories: Very easy, easy, medium, difficult, very difficult. 2wd Suv-Crossovers should pass very easy and easy trails without problems. Maybe they can also pass medium trails if the terrain is dry. Difficult trails require 4wd, good ground clearance ( 20cm at least ) and good approach and departure angles. In very difficult trails, low range is helpful to smoothly maintain low speed at some points, but not absolutely necessary. All trails have been passed with no problems or damages with a 2004 4wd Nissan X-trail T30 with All terrain tyres. Note that when very wet or snowy, even a very easy trail can be unpassable.