European trucks have been using adblue for a while now to clean up diesel emmisions and are starting to become more common in Oz. They have a separate smaller tank along side the diesel tank.
As opposed to the truck I'm in, which has a DPF filter as needs to perform a 'burn off' to clear it out by sitting stationary high idling at around 1800 rev's the system then squirts a bit of fuel in the red hot exhaust for 20 to 45 mins. However the filter now needs replacing at a cost of $3500. Some trucks filters are around $10000.

Speaking to my sister in Yorkshire her diesel Honda CRV has a similar filter which now needs replacing. The cost of which takes the shine off the benefit of lower fuel bills.
Something to bear in mind of what needs replacicing down the track when tempted by 'cheaper running costs'

Maybe cars will soon be running adblue to as there is a network already in place for it?