A process for preparing oil and petroleum-resistant cellular to solid (polyurea)polyurethanes (PURS) with improved physical properties in which a polyether polyol component having a number average molecular weight of from 1000 to 8000 and a polyester polyol component having a number average molecular weight of from 1000 to 6000 are reacted with a polyisocyanate and the (polyurea) polyurethanes produced by that process. The (polyurea)polyurethanes are particularly useful for personal safety equipment and in the construction of automobiles.