We analyse the non-catalytic soot oxidation kinetics predicted by four models implying, respectively, (i) monosized uniform spherically shaped soot spherules, (ii) monosized disk-like spherules formed of carbon sheets, (iii) spherically shaped spherules with a realistic size distribution, and (iv) disk-like spherules with a realistic size distribution. In all the cases, the reaction front is considered to move from the periphery to the center. The effect of the spherule size distribution on the oxidation kinetics is found to be appreciable and accordingly should be taken into account in interpretations of the corresponding experiments. The latter is illustrated by scrutinizing relevant experimental data and illustrating that model (iv) appears to be preferable. (c) 2008 Elsevier B.V. All rights reserved.