[LarryHughes]

I have recently installed the third radiator in my '01 996. Car is stock except for a K&N air filter and a low temp (160F) thermostat. Conditions described are all Florida weather, app. 90F. Radiators clean of all debris. A/C is on (fans running) during testing. Running the prescribed amount of Porsche Pentofrost coolant. Measurements are via a wireless OBD2 reader to my smartphone. No, my temperature sensor is not calibrated nor am I certificated in metrology but I think a reasonable person would agree this test set is indicative of results you might experience.

Even with the low temp thermostat, I typically saw 186-188F in town and at Interstate speeds 75-90mph. Nothing of concern but still I'd like more cooling capacity for when I track the car.

After installing the third radiator (Pelican's kit), there was no change in stop and go traffic. About 45mph, however, the temps begin to drop to low 180F. At Interstate speed I see 179F to 181F. I also observe that even at speed, if airflow from traffic disrupts airflow to the radiator, the temp will begin to creep up toward the 186-188F mark.

There is no discernable difference in the time it takes to warm up the car: the thermostat is throttling coolant flow to the radiators, of course. Cool down time wasn't measured but I doubt it is significantly different since no coolant is circulating with the engine off.