Know your truck.
Own the trail.

2H: rear-wheel drive

The transfer case sends everything to the rear driveshaft. The front axle freewheels because the hubs or axle-disconnect are unlocked.

Use it for

Dry pavement, highway, daily driving

Why

Least driveline wear, best fuel economy

4H: front and rear locked together

On a part-time system both driveshafts turn at exactly the same speed. There is no center differential, so the front and rear cannot slip against each other in a turn.

Use it for

Snow, gravel, wet grass, faster sand and mud

Avoid

Dry pavement — the driveline binds in tight turns

4L: same lock, plus gear reduction

Power passes through a reduction gearset in the transfer case, typically 2.5:1 to 4:1. Wheel speed drops and torque and engine braking are multiplied by the same factor.

Use it for

Steep climbs and descents, rocks, boat ramps, slow deep terrain

Speed

Keep it slow; many manuals cap 4L around 25–30 mph

AWD / Auto 4WD: front and rear can differ

A center differential or computer-controlled clutch pack lets the axles turn at different speeds, so it is safe on any surface. Auto modes add front torque when the rear starts to slip.

Use it for

Changing conditions, wet or icy roads, towing on slick highways

Note

Crossover-style AWD has no low range