I have a thought for you guys to ponder. Ford specs EOT and ECT should be within 15* once the vehicle reaches operating temp. I have noticed mine is around 9-10* difference with no load at freeway speeds. This is with a newly built oil cooler. However, my EGR cooler is deleted. Wouldn't this increase the spread by keeping the ECT a bit cooler as it is not cooling 750* exhaust gas???? Oil temp is around 200* on 90* day. Thoughts?????

 

Deleting the EGR cooler may make the engine coolant run cooler, but it won't have any effect on the spread. The oil cooler is just a heat transfer device, and how efficient it is at that (yours is new), determines the spread.

 

That's an interesting thought, but with the massive cooling system our trucks have I don't think deleting the EGR cooler is going to make too much difference in that spread, since coolant temp is regulated by the thermostat anyway.