Those strong tractors are called "towing tractor". It used be more common for those vehicles to pull air planes with a long bar attaching it to the plane, but the latest model called "Towbar less" has no bars. The size of the engine of the latest model of Towbar less tractor, WZ4000, is 515 hp. It is about the same size of the bulldozer, D375's engine. Towbar less can only go at 30 km/h when pulling an airplane due to the speed limit, however it actually has capability of running at as fast as 34 km/h.

It can move a jumbo jet despite its small body! Its power is equivalent to that of the bulldozer, D375.