Steve, in Australia we have what is called High-Flow diesel fuel pumps.

These have a larger nozzle and will not fit into a normal passenger automobile fuel tank hole.

High-flow pumps are usually grouped away from the main fuel pump with very high or no roofing, especially outback. I myself use high-flow to refuel my ute, otherwise I stand around for an eternity putting about 120 litres of diesel, whereas with high-flow, about 30-40 seconds is all it takes for me to re-fuel. When you pull up and the truck immediately in front of you takes $1,350.00 of diesel, you do not sit around very long waiting to use the pump; happened to me last year in outback Queensland.

High-flow is what is often referred to as truck diesel, but it isn't. I don't know what truck diesel is, but on major rural highways you will often see signs flogging truck diesel about 2 cents a litre cheaper. I have a suspicion that it is just a discount for what is a bulk purchase.