Radiators can add drag, but they can also add thrust which exceeds that drag. (https://en.wikipedia.org/wiki/Meredith_effect https://en.wikipedia.org/wiki/Mered

Radiators can add drag, but they can also add thrust which exceeds that drag. (https://en.wikipedia.org/wiki/Meredith_effect https://en.wikipedia.org/wiki/Meredith_effect).