Ive had 3 Triton utes over the last 10 years, lease them for work, I do about 50,000 k a year, with about 200kg of gear in the back of a tray back. I also have towed the infamous QVMX trailer about 2,200 kg, and my own van , about 2000 kg , for a lot of klm. I have also put 3 bikes in the back and towed boats up to Fraser is.
Ive had two diesels and a v 6 petrol. The diesels were good and strong but wouldn't like to keep them after the warrenty runs out for the many reasons mentioned above.
The current GLXR V6 hauls ass and is great to drive but a little heavy on the juice.
In summary, it depends on were your gunna drive it, diesels are better than petrol on the beach, apart from that petrol is the go.