<div class="section abstract"><div class="htmlview paragraph">Nowadays the mains techniques to obtain Sound Power of machines and equipments are: - Sound Power obtained by Sound Pressure and - Sound Power obtained by Sound Intensity.</div><div class="htmlview paragraph">This paper intends to compare results and show some advantages and disadvantages found during the tests.</div><div class="htmlview paragraph">This discussion will be based on heavy-duty diesel engines and the data show different results (Δ=2dBA) comparing ISO 3744 and ISO 9614, but allow us to have a correlation factor, at least for this engine type.</div></div>