ATF coolers, effectiveness

Comment from a guy at the local tranny parts house, that ATF coolers should be a parallel flow device, similar to a radiator...and not a serier flow device with a bunch of tubes going back and forth....

but if the tubes are ~1/2 inch dia and the input tubing is only 3/8 dia....

IS the flow restricted THAT much?? is it worth changing designs over this.???

I have a cooler with ten passes and 180* loop/bends through the fins....~1/2 diameter and 3/8 feed/exit...

so is it worth changing the cooler for heavy duty applications??? meaning towing and trucks....

:search:

I've used an old tube and fin a/c condenser before with no probs.
Presently I use a plate type 40,000 GVW rating, 45,000 BTU rating.
Most don't advertise their btu rating, the most important part.

Get it hot and measure the outlet temp would be best.
Be aware that there is a min gpm for the return to tranny so make sure it is not restricted, but sounds like you would be fine.
Don't know if I can find those specs, I'll try.

I have a tube and fin type and mistakenly put the temp sensor up stream of the cooler first. It would read 200*-220* in summer traffic. After moving it to the outlet side as per the tranny builder, the temp dropped to 150* or so in the same situation. Pretty efficient it seems to me?