[Abner]

Originally Posted by euromodder

Loads are regularly carried above large super-single wheels on many European trucks and trailers.

In a conventional truck the engine would be in the "tunnel", lowering the CoG.
But there's usually no such low-positioned mass on the trailer.

In a hybrid Tunnel-truck, the generators, fuel, batteries and electric engines could be in the tunnel walls, also lowering the CoG.

Yes