"The difference (besides any efficiency, blade direction, blah): the front-mounted pusher fan is an OBSTRUCTION to natural air movement at cruising speed - the car would be better off without it."
Panic,
It seems that air conditioned vehicles have condensors mounted to the front of the radiator that reduce the airflow through the part of the radiator behind the condensor more than a pusher fan would. Yet, when I added AC to my 1971 Dodge van 20 years after I bought it new without AC the temperature gauge did not indicate that the engine was running any hotter. That seems counterintuitive but it's hard to argue with a gauge. That old van is still going strong and even pulling a travel trailer at age 46 and about 355K miles. It's hard to beat the durability of old school Detroit iron.
It's generally agreed that pusher fans are less effective than pullers and I'm really curious why that is. In addition to an AC condensor some vehicles have even more obstructions like transmission coolers and even power steering fluid coolers in front of the radiator yet they have no overheating problems. So it appears that placing other cooling devices in front of radiators doesn't keep them from working effectively. How that can be is curious.
