Studies of sedimentation stability have shown that for additives containing smaller particles of powder components (30…50 nm) it is 1.32 times higher than for additives containing larger particles of powders (50…300 nm). The analysis of the experimental results showed that the modification of Lukoil 10W - 40 engine oil with the addition of L-60 brass powder with a particle size of 30...50 nm contributed to a 1.21-fold reduction in friction torque compared to Lukoil 10W–40oil mixed with L-60 brass powder with a particle size of 50...300 nm and 1.38 times compared to the base oil Lukoil 10W–40. The wear of samples (pads) after 3 hours of testing on base oil Lukoil 10W - 40 is 11.6 times greater compared to the wear of samples operating on Lukoil 10W–40oil with the addition of L-60 brass powder with a particle size of 50-300 nm. The test result of Lukoil 10W - 40 oil with the addition of L-60 brass powder with a particle size of 30-50 nm showed an increase in the mass of the friction sample (pads) by 0,3 mg. The addition of L-60 brass powder with a dispersion of 30...50 nm (2nd sample) to the base oil, after 3 hours of testing, led to a decrease in the temperature of the friction surface of the samples by 11 and 16% compared to the first sample (Lukoil 10W–40+ brass L60 (50 ... 300) and to the third sample (Lukoil 10W–40), respectively.