This paper presents the results of research on the propensity of E10 petrol (defined by EN 228 standard as a petrol with a maximum oxygen content of 3.7 wt.%) to form deposits in combustion chambers by using the method of determining the unwashed gum content EN ISO 6246 and by thermography TGA FLTM BZ-154-01. The aim of this is study was to examine samples of unleaded petrol 95 containing ethanol (EtOH) and/or ethyl tert-butyl ether (ETBE) improved with three different packages containing detergent additives derived from poly-succinic acid. The additive D3 containing imido-amid of polybutylene-succinate exhibited the best efficiency in reducing the propensity for fuel deposit formation in combustion chambers. Clear differences were found in how the presence of various oxygenating compounds can affect the efficiency of the thermogravimetric decomposition of gums. In the case of petrol containing ETBE as the only oxygenate, for the same levels of additives used, there was a reduced tendency to form deposits (CCD) than for the same type of petrol fuel with ethanol content. (C) 2015 Elsevier Ltd. All rights reserved.