The relevance of the matter is confirmed by numerous researches of the alternate engine fuel, in particular, from the renewable sources of raw materials (biomass) studied in various regions of the Russian Federation and abroad. For obtaining diesel composite fuel as raw materials are attractive oil crops which are not used in the food industry, for example, carthamus, false flax, colza, winter cress, crambe and castor-oil plant.
At the moment the need for the ricinic oil used in military, chemical, machine-building, radio-electronic, printing, paint and varnish, medical, cosmetic and other industries in the Russian Federation grows. As a result of processing of a castor-oil plant fruits by cold press in residual meal or pod there are about 10% of oil which is possible for allocating by processing of meal on technology of extraction with receiving technical ricinic oil with a possibility of application as raw materials for receiving paint and varnish, lubricants and diesel composite fuel.
However viscosity of ricinic oil is 10 times more, than at diesel gas oil therefore it is necessary to apply in mix with low-viscosity components. As additive to ricinic oil can be used mineral oil fuel and bioethanol due to which mixture viscosity considerably decreases, cloud point and crystallizations temperature decreases. 
As diesel composite fuel is investigated mixture of ricinic oil (RicO), and summer diesel gas oil according to National State Standard 305-2013. On the basis of the carried-out calculation are defined indexes of a working cycle, dependences on concentration of components of blenderized fuel are shown.
On the basis of the calculation, are determined the working cycle indexes, are shown the dependences on the concentration of the components of the composite fuel. Based on the results of the calculation, the obtained indicators were compared with diesel gas oil.