The most significant conflict between experimental and simulated results in the non-turbid region is for the CAPB / SLSar mole ratio 4.0. Here, the simulation suggests that the system should have an elevated zero shear viscosity based on the aggregates at other mole ratios. The laboratory data measured for this work reports low viscosity at all pH levels sampled. This may be because the samples of CAPB used in the experimental work in this study were impure (the models are 100% pure), as is almost always the case with commercial surfactants. Work performed by Lu et al. shows that the CAPB / SLSar mole ratio 4.0 (albeit for a different total surfactant loading of 12 %) should, in fact, lead to a increased viscosity. Therefore it is possible that the simulation here is correct and the experimental data has been affected by the choice of materials and measurement approach (this in itself is useful information). Dwelling a little longer on the results from Lu et al. , we notice that these differ slightly from those reported here. This may be due to subtle differences in the composition of the surfactants used, or in the rheological test methods employed. It is also possible that the differences are due to the fact that Lu et al. used a total surfactant concentration of 12 % whereas we sample at 15 %. Despite the differences the trends are the same: moderate richness of CAPB leads to higher viscosity at the correct pH whereas adding too little or too much does not, and the optimum mole ratios of CAPB to SLSar are similar.