In this talk, I will briefly introduce our recent Valparaíso ALMA Line Emission Survey (VALES) project as well as the new APEX/SEPIA Band-5 observations targeting the low-J CO emission line of 63 Herschel-detected galaxies at z~0.15. We investigate the star formation efficiencies (SFEs = SFR/M(H2)) of galaxies at low redshift. We find the SFE of our sample bridges the gap between normal star-forming galaxies and UltraLuminous Infrared Galaxies (ULIRGs), which are thought to be triggered by different star formation modes. Considering the SFE as the SFR to L(CO) ratio, our data show a continuous and smooth increasement as a function of infrared luminosity (or SFR) with a scatter about 0.5 dex, instead of a steep jump with a bimodal behaviour. This result is due to the use of a sample with a much larger range of sSFR/sSFRms using LIRGs, with luminosities covering the range between normal and ULIRGs. We conclude that the main parameters controlling the catter of the SFE in star-forming galaxies are the systematic uncertainty of the α(CO) conversion factor, the gas fraction and physical size.