I never got the specifics from you 3 years ago when I asked the same question: How do you know exactly when the grille shutters open & close?The shutters close somewhere around 45 MPH and will then remain closed until the car needs additional cooling. Like Merc, my shutters stay closed for long periods in the winter.
I ran across the speed for shutter closure back in 2011 when the Cruze ECO was the rage in the automotive media. It actually makes sense as this is about the time most ECO drivers shift to 6th gear if they're driving for efficiency. As for the reopen, I know for a fact that the shutters in my ECO MT don't open during serious cold snaps in the winter. Once closed they appear to stay closed until the cooling is needed.I never got the specifics from you 3 years ago when I asked the same question: How do you know exactly when the grille shutters open & close?
I like what you have done! I have added a grill block to mine as wellI am monitoring radiator return water temperature, and nearly all of my front grill is blocked except for the little band at the top of the lower shuttered louvers.
Peak temperature returning to the engine has been only 42 deg C, at 60MPH with 106 measured at ECT, outdoor air temp was low teens.
the image is not pretty, still at the experimental stage.