JU 87 and Water radiators
 

How can I tell how open or closed the water radiators are(besides the temp gauge)?

They operate the same as a 109 but the only animation I can see is a button press.

press and hold untill the gauge (other side of the dashboard) show open (AUF)...

Yep, they are electrically operated and have a position indicator at the upper right side of the instrument panel.

But beware!! They work only if your engine is allready running. If you want to open your radiator before you start your engine you will most certainly cook your engine soon after start. ;)

I do not know why I did not notice that dial before, might make things a little easier :)

Also a question regarding the oil radiators. Do they affect drag or should I just keep them fully open?

Thanks for the replies.