In the last twelve months, and after the usual servicing/cleaning/flushing.
Nissan Patrol GU/Y61, TD42T engine.
Out, Caltex (Texaco) ELC (Dexcool for those in NA)
In, Cummins/Fleetguard PG Platinum HD coolant.
Land Rover Defender, 300Tdi.
Out, Caltex ELC.
In, Cummins PG Platinum.
Soon;
Fiat 550 tractor.
Current coolant, Prestone conventional.
Soon to be superseded by, surprise, surprise, Cummins PG Platinum.