Adopted from 4×4 Routes of Montana – Montana4x4trails.com
Class 1 – Two wheel drive, high clearance is adequate. You can do this trail in a Subaru.
Class 2 – Four wheel drive will be required at some point.
This hill is an example of 2-2.5 difficulty
Class 3 – Four wheel drive is a requirement, some driver experience is needed, 31 inch tires are highly recommended.
Class 4 – A difficult route. At least one locker, good off road experience, 33- inch or larger tires, having a winch becomes a requirement.
This hill is an example of what i would consider 3.5-4 difficulty.
Class 5 – A VERY difficult route. Lockers front and rear, extensive driving experience, winch and at bare minimum 35-inch tires. Body damage or mechanical failure may occur. I don’t drive a buggy, and wont try anything near this in my daily driver.
Weather conditions can increase the difficulty level. Different times of the year can increase the difficulty level. Some trails maybe relatively easy, but with a HIGH penality for failure, Such as high narrow mountain roads that are feet away from 1000 foot clifs. This scale does not take into account these dangers.
It is important to understand the capabilities and limitations of your current vehicle. Different vehicles and driving styles may have different requirements. The above difficulty scale is based on the authors scale used in 4×4 Routes of Montana. The author owns a purpose built Willys Jeep and a Jeep ZJ. Take this into consideration when making plans. For example, a short wheel based JK may only need 31 inch tires and have less difficulty with obstacles because they can simply drive around them. Your double cab tacoma might need bigger tires, sliders, and armor to complete the same trail, depending on the owner’s comfort level when it comes to boulder contact with underbody components. We all know that a stock 80 Series LC can go anywhere if you have the factory locker dial so you do not need worry if you drive one of those.