Certain low‐frequency asymptotic relations originally derived from the K‐BKZ model for parallel and orthogonal superposed flow are evaluated with experimental data and in terms of the predictions of six additional models. For orthogonal superposed flow, Tanner and Williams show that the data are consistent with the asymptotic relation, and it is shown here that all six additional models also predict this relation. For parallel superposed flow, the author's data are in conflict with the K‐BKZ model relation, and it is shown that only three of the additional models correctly do not predict this relation. These models (the Bird‐Carrreau model, the WJFLMB model, and the generalized pearl‐necklace model of Booij) also are the only models not to predict the general relation between the complex moduli for parallel and orthogonal superposed flow derived for the K‐BKZ theory by Yamamoto and Takano and by Bernstein. Analysis shows that the low‐frequency asymptotic relations jointly can be considered a special case of the general relation, and that, therefore, it is expected that the general relation will be rejected when parallel and orthogonal superposed flow data become available for the same fluids.