Star formation efficiencies, (left y-axis), or molecular gas depletion timescales, t_depl = SFR/M_gas, assuming a “Galactic” CO–H₂ conversion factor for all galaxies (right y-axis), as a function of galaxies’ offsets from the main sequence, sSFR/ sSFR_MS, plotted for our low-L_IR-selected SFGs (squares) and our comparison sample of z> 1 SFGs with CO measurements from the literature (triangles). The shaded area defines the accepted thickness of the MS, i.e., a scatter about the SFR-M_∗ relation between 0.3 < sSFR/ sSFR_MS< 3. The enlarged sample of z> 1 SFGs confirms the general trend of higher SFE for galaxies with larger offsets from the MS with a Kendall’s tau probability of 0.025 percent. However, considering MS galaxies only within the shaded area, their SFE appear roughly constant, given the Kendall’s tau probability of 0.23 percent with a large dispersion of 0.32 dex.