Methodological basis and results from the experimental studies on hydraulic and friction resistances under turbulent supercritical-pressure (SCP) fluids flow in round tubes under adiabatic and heating conditions are presented. The experimental technique and results from sounding studies of the averaged turbulent SCP fluids flow under normal and deteriorated heat transfer conditions are given. The possible sources of large errors in hydraulic resistance calculations, when using one-dimensional (homogeneous) flow model, are pointed out. The interdependence between the heat transfer deterioration and significant changes in the averaged flow structure due to fluid thermal acceleration and Archimedes forces effects is analyzed. (C) 2012 Elsevier Ltd. All rights reserved.