Cooling without a fan!

I didn't know this was possible. I replaced an electric radiator fan on my ricer SUV and let it idle for a half hour with the AC off. The temperture gauge stayed slightly below the middle and so the fan never kicked on. I asked my neighbor and he said if the radiator is super efficient then it can cool the car without a fan even at idle. Has anyone else had this experience?
 
Speaking of running into it at work....

It's annoying as hell. Trying to fix a fan, replace the unit, turn the car on to see if the fan kicks in at the right temperature, and BAM, the car is cooling itself without a fan. Really sucks sometimes.