This Mecra LongBoi should have the most amount of torque you can get from an automation engine, put into a sleeper cab truck. 10 tires, detachable middle axle, lockers, and still not enough traction. So there's a setting to increase the grip, and more.
It should have a functioning fifth wheel, but BeamNG is bugged for me, so I couldn't test it.
Here's the build video, and how it runs -