Fuel consumption vnl d13

This! I would say check the thermostat as well. Try covering the radiator maybe?

Did the problem start recently? Are you driving in a different climate? Different road type?

 

I seen this happening already in fall when there was 70 deg outside and I idle with ac on temperature will go down under 170 and truck will raise idle to warm up. When it got colder to about 30-40 degree If I drive small down hills the temperature went around 130. No faults. Replaced thermostat and after that it at 170. Mine fuel milage went up .4. I have car haulrer so the best i see now it’s 6.5.

 

What does the dash show fuel use at idle with engine at normal temp (170°-180°)

 

Did anyone make sure to check boost system and air to air make sure it’s not broke or has leaks that will tank your fuel economy.