Mechanical losses tests are conducted on the dynamic dyno, where the measurement of torque needed for a combustion engine running under set conditions is possible. The aim of the test is to define the influence of the engine oil in use on the engine’s mechanical efficiency and the reduction of frictional losses. The choice of engine oil also influences the engine’s fuel consumption – and thereby CO2 emissions. The results permit improvement of the lubricating properties of engine oils through quantifying the influence of individual oil additives on the friction within the engine.