Fluidity of aluminum alloysAluminum alloy is typically measured by spiral test moulds. This requires several different parameters to be tested in an aim to compare the change in the fluidity. In this work, newly proposed quadro mould design was investigated where a stopper was used to ensure same metallostatic height and four different channels were cast with different thicknesses: 3–4–5 and 6 mm. A356 alloy was used and Er content was set to 0.1 wt% whereas Eu was 0.3 wt% to evaluate the fluidity characteristics of the alloy. Overall, four different conditions were tested: A356 base alloy, 0.1 wt% Er, 0.3 wt% Eu, and combined addition of Er and Eu (0.1 wt% Er+ 0.3 wt% Eu) were analysed. In all channels, Er containing alloy revealed the highest fluidity. However, no significant improvement was observed in fluidity when Eu was added to alloy. Additionally, Gage R&R analysis were carried out to evaluate the effect of operator on the tests, and it was found that the mould design was free from operator factor.