lolder Report post Posted February 11, 2015 (edited) It appears that there are two sections to that radiator; the upper half for the electric powertrain cooling which uses coolant fluid and the lower half for the transmission fluid ( oil ) cooling. It is of interest why Ford didn't worry about transmission fluid cooling/circulation in the HEV while towing and yet did in the PHEV EnergI under normal operation. The electric powertrain would not need much cooling while towing but one would think the transmission fluid circulation should be the same because all the same gears and bearings are turning. We don't know enough about this yet but three transmission failures on this forum are three more than I would expect. There were a number of failures in 2004+ Ford Escape hybrids most attributed to a faulty motor electronics coolant pump which caused "Pull over Now" warnings. Edited February 11, 2015 by lolder Quote Share this post Link to post Share on other sites