Organisers said the high-octane, adrenaline-pumping, on-field action had gone down a treat with show goers on the Saturday and the fans were back for more of the same.

''Revenge'', a 4.5-tonne, 1200-kilowatt, $280,000-plus Monster Truck, was easily the meanest machine on campus and certainly the most dangerous.

Kreg Christensen, a ''fly in'' driver for EMT Events' Monster Trucks Australia, said because of their size and weight the monster trucks were inherently unstable when they were jumped. Concentration and quick reflexes were the name of the game.

''You've got be pretty ambidextrous,'' he said. ''Driving one of these is a lot like walking, patting your head and rubbing your tummy all the same time.''

After 22 years at the helm of the big crowd-pleasers Mr Christensen is always mindful of the fact they can bite back in an instant if his mind starts to wander.

He had a remarkable escape during a world championship event last year that resulted in his vehicle flying 40 metres into the air before crashing, nose first, into the earth.

''I broke my T1 rib and it smashed me in the throat,'' he recalls. ''You get whiplash every weekend.''

The danger has never discouraged him from performing.

''My wife says I am like Dr Jekyll and Mr Hyde,'' he said.

''When the helmet goes on I lose my mind.''

At 48 he has no intention of giving the game away.

''This is all about putting a smile on a little kid's face and, when you think about it, there is a little kid in all of us, including me.''

Based in Willard, Utah, Mr Christensen said the best part of his job was being able to travel the world driving other people's machines.

''Before I started in this [sport] I had been motor racing for about three or four years,'' he said.

''I couldn't help noticing the drivers of the trucks were more popular with the fans, got paid more and appeared to spend less time working on their machines than the race drivers.

''It turned out that only the first two of those things was true. These do take a lot of work.''

He built his first truck, a beefed up Chevy Silverado, from the ground up having bought a standard vehicle to work from. ''It was white and green and had a knight painted on the side,'' he said. ''It was named by the students at my kids' elementary school. They called it Dragonslayer.''

Revenge, which made its debut in Canberra this weekend, is one mean machine. Its tyres are almost 1.8 metres in diameter, and the nine-litre Chevy V8 delivers its power through a two speed Powerglide gearbox.

It also has another attraction for Mr Christensen. ''It's not mine,'' he said, ''If something breaks I don't have to fix it.''

While the Hondas of the Showtime FMX bike spectacular can't match Revenge for sheer grunt, they fly faster, higher and further than any truck could.

Riders Brad Burch and Kain Saul, both veterans of Crusty Demons and Nitro Circus, appeared to defy gravity as they launched their new machines high into the air on Sunday afternoon.

Somersaults, no-hands flights through the air and perfectly timed take-offs and landings were all part of a demonstration that made the impossible look remarkably simple.

The final part of the motorised entertainment program was based around two of the last Australian V8 utes, a Holden and a Ford, that ran through a slalom course before a demonstration of dirt track sliding.

The orange Ford was driven by Matt Luke and the red Holden was driven by Gary Baxter.

While final attendance figures at the show were not available on Sunday evening, it was expected more than 100,000 would have passed through the gates, which appears likely to pip last year's centenary turnout. One reason was the perfect weather a spokeswoman said.

''It couldn't have been better,'' she said. ''It hasn't rained and it hasn't been too hot either.''