I daresay many readers are familiar with the sport of tractor pulling. Wikipedia describes it as follows:
All tractors, in their respective classes, pull a set weight in the sledge. When a tractor gets to the end of the 100 metre (300 feet) track this is known as a "full pull". When more than one tractor completes the course, more weight is added to the sledge, and those competitors that went past 300 feet will have a pull-off; the winner is the one who can pull the sledge the farthest.
The sledge is known as a weight transfer sled. This means that as it is pulled down the track, the weight is transferred (linked with gears to the sledge’s wheels) from over the rear axles and towards the front of the sledge. In front of the rear wheels, there is a "pan". This is essentially a metal plate and as the weight moves over this the resistance builds. The further the tractor pulls the sledge, the harder it gets.
There's more at the link. Here's a video clip of a tractor pull to illustrate it, for those who may not have seen it before. (Note how the glass of the sled cab shatters as the specially modified tractor's outsize wheels throw a rock back into it, to the obvious discomfiture of the sled operator.)
Some of the 'tractors' are so heavily modified and souped-up that they resemble nothing less than science-fiction spacecraft! Here's one from a Dutch tractor pull last year.
It seems a Leopard 2 tank of the Dutch Army tried its hand at a tractor pull in the Netherlands a couple of years ago. A modern main battle tank, with its tracks, heavy armor and (in this case) a 1,500hp turbocharged diesel engine, is a whole different breed of animal when it comes to tractor pulling, as the video clip below illustrates.
OK, that's pulling power! Good thing there was an earth berm at the end of the track to stop them, or they might still be under way!