A 4th core in the radiator doesn't cool much, if any at all.
The first row gets nice cool air. The second row gets warm air that picked up heat from the first row. The third row gets hot air that picked up heat from the first two rows. The fourth row gets air that is the same temperature as the water that's passing through it.
All a fourth row (and sometimes 3rd row) does is add capacity.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
