Heat exchanger tubes are disclosed herein. An embodiment of a heat exchanger tube includes a tube body having two opposed sides. A plurality of exterior flow passages is defined in the tube body adjacent one of the two opposed sides. A plurality of interior flow passages is defined in the tube body adjacent the plurality of exterior flow passages. The plurality of exterior flow passages has at least one of an average hydraulic diameter or an average width that is i) greater than at least one of an average hydraulic diameter or an average width of the interior flow passages and ii) less than twice the at least one of the average hydraulic diameter or the average width of the interior flow passages.