What is Diffrential Lock?

[MagnusA]

I got stuck in a 90 degree intersection with my articulated double. The game suggested to turn on "differential lock" (key V). Somehow that helped getting unstuck but what it is or what does it do?

Have a a 6x4 truck with automatic gearbox and mouse steering if that matter.

[Kristian]

It locks your driven wheels, so they all spin equally. Prevents one-wheel-wheelspins etc

[Reese]

Differentials in vehicle allow multiple wheels to spin at different speeds. This reduces the room needed to turn, reduces skidding of the wheels, and in general makes for a better driving experience. Differential lock will instead lock the wheels to spin at the same speed. In practice, this means all of your wheels will spin, regardless of traction. If you're stuck and only 1 wheel is spinning(the wheel with the least resistance), you can't really do much. But enable Differential Lock, then your wheels will spin regardless, which can help you get unstuck.

In some situations, diff lock can hurt. Less power to each individual wheel. But most of the time, it'll help you get unstuck since at least 1 powered wheel will be in contact with the ground.