It is noted, that optimization of parameters of working system of multi-based irrigation machines “Fregat” and “Kuban-LK1” is based on studying the system “rain-surface-DM”, inferencing indexes of energy-connecting car qualities. Questions of influence of the degree and height of soil-connections on the underlined characteristics are discussed. The data of   laboratory researches is presented, that let judge about practical absence of soil sticking on tires by means of powerful washing by artificial rain. It is stated that irrigation - machines provide necessary energy – connecting qualities in the whole range is irrigation norms. Their increase is observed in cases of elevated water supply (400 m3/ga and more) and in cases of changing the direction and height of soil – connections.