Trails We've Run

Rating Scale:

Potholes, minor wash outs, medium sized rocks and mud holes.
Higher ground clearance helpful. Vehicle and Equipment Passable by most stock 4x4 vehicles.

Loose gravel, large pot holes, steep inclines, medium sized rocks.
Four wheel drive required, tires with aggressive tread and lowered tire pressure helpful.

Some rocky sections, bypasses at most major obstacles. Some body damage possible. Rocker panel and rear quarter panel protection helpful.
Upgraded bumpers (Useable as a hi-lift point), rocker panel skids, skid plates, Hi-Lift, 32" Tires, Rear locker

Frequent ledges, crevices, large boulders, steep inclines and off camber situations. Body and or tire damage likely. Spotters may be needed for some obstacles. Low tire pressure required, good chance of loosing a bead. Possible component breakages.
Front locker, 35" tires, upgraded axles, lower ring & pinions, transfer case gear reduction (w/ manual transmission), winch, recommend spare axles, recommend spare steering parts

Same as a 4.0 rated trail but the obstacles are bigger, tighter squeezes and bigger risks to body and mechanical components. Few bypasses if any. Longer wheelbase vehicles may have problems with breakover angles, short wheelbase vehicles may have to use a winch or strap on some obstacles. Large vehicles will damage sheet metal. Spotter may be needed for all major obstacles. Rollovers possible. Plan for common component breakages (vehicle specific).
38" Aggressive off-road tires such as Swamper/Bogger/MTR, D44 or better axles, source for on-board air, beadlock rims, flexible suspension, wider than stock track width.

Same as a 4.5 rated trail but the obstacles are bigger, tighter squeezes and bigger risks to body and mechanical components. No bypasses. Body damage guaranteed. Spotters needed for most of trail. Rollovers likely. Some obstacles may require a winch for larger vehicles. Trail may be impassible when wet. Plan for major component breakages.
Realistically these trails should be run with rock buggies. Aggressive off-road tires such as Swamper/Bogger/MTR. Transfer case gear reduction (w/Automatic transmission). Remove all unneeded body parts. 100" Wheelbase.

This type of run is pushing the outer limits of what is (currently) possible. This is the same as a 5.0 rated trail except all of the obstacles are bigger. Constant spotting required, vehicles will get hung up frequently, undercarriage will catch rocks. At some point a winch will be required to support the full weight of the vehicle.
Light rock buggy.