I have a 1997 Toyota Landcruiser 3.0 td..Driving in town at speeds under 50 mph it is fine however on a run if taken over 60 mph it starts to overheat also towing will make it overheat too..It uses no water and if it overheats simply reducing the speed to under 60 mph drops the temp down to middle on the gauge..No water leaks,fan seems fine..It is a UK spec vehicle.

the only thing i can think of is that you have a hose sucking shut probably the top rad hose check it to see if it feels spongy