Interesting video. Nice to see XPTs with their full compliment of 7 carriages. I wonder what the driver was handing to that guy with the rucksack upon arrival at Wollongong 0:20 Unfortunately drivers aren't quite as friendly in the UK, well not in Southern England anyway.
It's a DEMU (Diesel Electric). The XPT power cars are extensively modified from the BR Class 43 for Australian conditions. To cope with larger gradients the traction motors are lower geared resulting in a design speed of 160 km/h (99.4 mph); the engine cooling capacity doubled; revised engine air filtration; longer travel, more compliant suspension fitted to deal with poor tracks; stronger frontal collision protection and nice business like sounding horns are the main points I recall. Originally fitted with Paxman `Valenta', all power cars were upgraded to Paxman `VP185' around 2000 giving better fuel economy and less Diesel / lubricating oil smoke, also there is a weight saving of approx. one Tonne per engine. The power cars are mated with carriages based on a Budd design that appear to have a larger loading gauge than for IC125 , including Sleeper accomodation; power cars & carriages manufactured in Australia. Check out `XPT by COMENG' (3 videos) here on RU-vid if interested.
