in the production of low - molecular olefins , in particular of ethylene and propylene , an educt stream containing at least one oxygenate and an educt stream containing at least one c 4 + olefin are simultaneously converted in at least one identical reactor on an identical catalyst to obtain a product mixture comprising low - molecular olefins and gasoline hydrocarbons . the ratio of oxygenates in the educt stream to c 4 + olefins in the educt stream here is 0 . 05 to 0 . 5 and is calculated according to the following formula : v = ∑ j ⁢ k oxygenate - j * n oxygenate - j ∑ i ⁢ k olefin - i * n olefin - i + ∑ j ⁢ k oxygenate - j * n oxygenate - j with : k oxygenate - j : carbon number of the oxygenate j n oxygenate - j : molar flow rate of the oxygenate j k olefin - i : carbon number of the olefin i n olefin - i : molar flow rate of the olefin i .