This article presents the results of measuring the calorific value and the rheological characteristics of Plantohyd bio lubricants. Measurements were conducted under laboratory conditions with an IKA C5000 calorimeter and a DV-3P Anton Paar digital viscometer. Results are presented graphically. It is shown that the physical interpretation of energy values results ​​and the dependence of rheological properties on temperature can be used to assess the quality of lubricants.