Use of a solid additive-filler - ultradisperse diamond-graphite powder (UDP-DG) - in lubricants is proposed for increasing the efficiency of operation of tribological couplings. The particle is 2-12 nm and the specific surface is under 400 m(2)/g. It is manufactured from explosives with an insufficient oxygen balance. The results of laboratory and bench studies and industrial tests confirm the high efficiency of UDP-DG as a multifunctional additive to motor, transmission, and industrial oils, plastic lubricants, and coolants for processing metals by cutting and pressure.