Ceramide synthase that catalyzes the transfer of the fatty acyl chain from acyl-CoA to a sphingoid base, with high selectivity toward palmitoyl-CoA (hexadecanoyl-CoA; C16:0-CoA) (PubMed:17609214, PubMed:17977534, PubMed:23530041, PubMed:26887952, PubMed:31916624, PubMed:39528795). Can use different sphingoid bases as substrates for ceramide synthesis, such as sphinganine in de novo synthesis, and sphing-4E-enine (sphingosine), (4R)-hydroxysphinganine (phytosphingosine) or sphinga-4E,14Z-dienine in salvage pathways (PubMed:17977534, PubMed:23530041, PubMed:26887952, PubMed:31916624). Other fatty acyl-CoAs such as long-chain saturated stearoyl-CoA (octadecanoyl-CoA; C18:0-CoA), myristoyl-CoA (tetradecanoyl-CoA; C14:0- CoA), and monounsaturated oleoyl-CoA (9Z-octadecenoyl-CoA; C18:1-CoA) can also act as acyl donors, but with less efficiency than hexadecanoyl-CoA (PubMed:39528795). Ceramides generated by CERS6 play a role in inflammatory response (By similarity). Acts as a regulator of metabolism and hepatic lipid accumulation (By similarity). Under high fat diet, palmitoyl- (C16:0-) ceramides generated by CERS6 specifically bind the mitochondrial fission factor MFF, thereby promoting mitochondrial fragmentation and contributing to the development of obesity (By similarity). {ECO:0000250|UniProtKB:Q8C172, ECO:0000269|PubMed:17609214, ECO:0000269|PubMed:17977534, ECO:0000269|PubMed:23530041, ECO:0000269|PubMed:26887952, ECO:0000269|PubMed:31916624, ECO:0000269|PubMed:39528795}. This is the function of CERS6 (ceramide synthase 6, ENSG00000172292).