When the ambient temps are cold, that is when the factory ATF cooler in the radiator helps the most.
I never heard of a 'cold side' of a radiator.
Extra heat is extra heat. The radiator fluid will warm up and be warmer than the cold ambient air that the aftermarket cooler alone is in contact with. It therefore has to help heat up the transmission fluid better. No way around it.
And remember, all aftermarket coolers want you to also utilize the factory one in series.
I never heard of a 'cold side' of a radiator.
Extra heat is extra heat. The radiator fluid will warm up and be warmer than the cold ambient air that the aftermarket cooler alone is in contact with. It therefore has to help heat up the transmission fluid better. No way around it.
And remember, all aftermarket coolers want you to also utilize the factory one in series.