I am talking an auto R51 Pathfinder here so pretty directly comparable.
I use OD when towing but at the very first sign of lugging I give the throttle a twitch to make it unlock the torque converter, if it is going to be extended I flip over to the manual mode which disables the lockup and manually gear down as required.
I just towed a 1700kg race car and trailer from Melbourne to Adelaide and back, mostly at the speed limit and with a 13.3l/100 average fuel consumption.