As to the answer to the above riddle: This is a semi-truck trailer that has a massive battery pack (up to 600 kWh) installed in its floor, and that battery powers an electrically driven axle ...

The spikes on semi-truck wheels are covers that protect lug nuts from road debris. They may also encourage drivers to give trucks extra room on the road.

Semi-trucks didn't start out with diesel engines, but there are specific reasons why the majority of semi-trucks on the road today use diesel engines.

A third steering method involved locking the trailer’s fifth wheel, keeping the trailer straight, and then turning all four wheels with each other, creating a straight truck.