Catalyzes the hydrolysis of acyl-CoAs into free fatty acids and coenzyme A (CoASH), regulating their respective intracellular levels. Preferentially hydrolyzes acetyl-CoA. acetyl-CoA + H2O = acetate + CoA + H(+) butanoyl-CoA + H2O = butanoate + CoA + H(+) H2O + hexanoyl-CoA = CoA + H(+) + hexanoate Allosterically regulated by ATP (activator) and ADP (inhibitor) (PubMed:11322891). Cold labile, it dissociates into inactive monomers at low temperature (PubMed:6136404). Lipid metabolism; fatty acid metabolism. Homodimer or homotetramer. By 2-(p-chlorophenoxy)isobutyric acid (CPIB).