First of all, bear in mind that every circumstance is unique, every recovery is special, and it is up to you to choose if the situation is safe.
Off roaders should calculate the weight of the stopped vehicle before recommending a safety rating that is somewhere between 1.5 and 4 times that weight as a starting point when trying to size the appropriate rope for them. We advise a little higher on that range for lightweight cars and the lower end for large machinery.
Most people may think this is counterintuitive, and they may question, "On heavier equipment, wouldn't you want a stronger breaking strength? "Yes, greater safety is always desirable, but we must also consider the quantity of nylon between the disabled car and the rescue truck, not only the breaking strength. The greater the amount of nylon between the two vehicles, the more effectively the energy is transferred and the less work required to extract it.
Other considerations that should be considered when choosing sizes include soil type, intended usage such as for recreation, agricultural, or commercial, and extraction vehicle type. Because the friction coefficient of beach sand, snow, or wet mud varies substantially when calculating friction and suction, soil types can play a significant role.