We comment on the shear stresses of recently reported Na-doped, Zr-doped, Al-doped, and Ce-doped TiO2-based electrorheological (ER) suspensions under applied electric strengths. Using deduced critical electric-field strength and additional scaled parameter, we found that the shear stresses could be analyzed using the universal yield stress equation, collapsing the data of Na-doped, Zr-doped, Al-doped, and Ce-doped TiO2 ER fluids onto a single curve