It depends what thermostat you have, and on the rest of your cooling system.

There's not really a temperature it "needs to" run at, but as long as you keep it below 210 on the hottest summer day you're doing well. If it runs somewhere at 160-180 on the highway on a typical day that's perfect.


1946 GMC Pickup - S-10 Frame, 455 Buick, TH400, original patina.

My 46 GMC on Photobucket