new dual core radiator????

[danger132ranger]

so i put a new dual core radiator in my 96 4.0l ranger and its been running just above the cold line all the time. I have noticed my mpg has dropped would it be possible the computer is trying to warm it up all the time now?
when i bought it, it was always sitting dead center of the gauge with the stock on.

 

[RonD]

A larger rad can help prevent overheating on hot days or when pulling heavy loads.

The thermostat is what sets the minimum operating temperature.
Ford's usually use a 192-195deg t-stat

So t-stat remains closed until engine coolant reaches 192deg at the t-stat, then it starts to open and circulate coolant through the rad, it will usually close again as coolant temp drops below 192, then open again until it finds a stable temp around 200deg.

Running engine below 190deg causes more fuel to be used, it gives you more power but power = more fuel.
Many run 160deg t-stats for this reason, to get more power, but if fuel economy is what you are after then get a 192deg t-stat.

Best fuel economy and oil lubrication is when engine coolant is between 200-220deg, oil viscosity is measured at 212deg.

It reads like you either have a 160deg t-stat or the t-stat is stuck open.