Technical Typical Coolant temperature

[YuriiGT]

Hi Guys! Since my searching around google and this site was not really successful I have question about my Ducato 250 2009

What is a typical coolant tepmerature of 3.0 aka 160 multijet during steady highway speed around 120kmh? Our car is doing maximum 74°C at outer temperature 5°C (OBD measurement)
Temperature needle on the cluster is quite under the middle position and the car is struggling with quite high fuel consumption.

In my oppinion temeprature should be around low 90s to optimal functionality of engine and fuel dosage.

Is my suspicion about faulty thermostat right or am I mistaken?

 

[whine0]

Hi on 3litre Ducato at full running temp the gauge needle on instrument cluster should be in the middle ,is the radiator fan constantly on ? Wouldn’t be to expensive to try new thermostat and temp sensor

 

[YuriiGT]

Thank you for advice... Radiator fan seems constantly off. I just tested our MY16 Jumper 2.2D (not same engine but I wanted to test another diesel powerplant) and its temperature oscillates around 90°C even at continuous full throttle for 5 mins. So my assumption about operation temperature seems to be right.

I had similar problems with my Audi 1.8T recently and thermostat change solved bad consumption and full throttle temps around 70°C, now its between 90-100°C