In recent years, the demand for increased performance from engines has been continuing growing, demanding more and more from the materials that are used for the engine assembly. Compacted graphite iron has become even more relevant material for diesel engine blocks and heads, with increasing combustion pressures required for reducing emissions. Therefore, the need to understand this material and how its microstructure is formed during solidification to prevent defects and increase resistance is constantly growing. A previous study is reviewed to understand the influence of two important process parameters on the microstructure formation near shrinkage critical areas in engine blocks, the magnesium content, and the amount of inoculation. One of the important conclusions of this study was that increasing inoculation could increase the homogeneity of the compacted graphite eutectic cells, without increasing nodularity or tendency for shrinkage formation. The present study aims on developing a methodology to study the influence of carbon equivalent on the effect of inoculation. Specifically, how increased levels of carbon equivalent increases nodularity using the same amount of inoculant and how setting a limit for carbon equivalent could allow the foundrymen to optimise the inoculation process, obtaining a more homogeneous microstructure, leading to increased mechanical resistance and less prone to shrinkage porosity formation.