Using potential energy of gases which worked in ICE and are discharged into atmosphere, it is possible to promote their efficiency and power. For transformation of potential energy of worked gases to mechanical it is suggested to use utilizing gas turbine. Two variants of expansion of gases in turbine are examined: to atmospheric pressure and to lower pressure, which is created by vacuum pump in receiver-cooler of gases, worked in turbine. For moving off the gases, which expanded in turbine to pressure lower than atmospheric, their cooled in receiver-cooler and compressed by vacuum pump. Adding by the system of transmissions the billow of gas turbine to the crankshaft of engine, it is possible to raise efficiency and power of the last. So, thermal coefficient of efficiency of improved installation, the ICE of which has characteristics ε=15, λ=1,4, ρ=1,2 and working at initial parameters of air t1=30°C and p1=0,101325 MPa at pressure in the receiver-cooler of 0,07 MPa, arrives 82,1%, and increase of work is 27,9% as compared to work of the same ICE before improvement.