On the basis of published reference data on crude oils recovered from more than 300 Russian oilfields, the effect of the concentrations of paraffin waxes, resins, and asphaltenes on oil properties has been analyzed. There are correlations between the oil density, viscosity and the resin content, whereas the amount of asphaltenes (along with resins) has a greater effect on the oil quality characteristics, such as sulfur content, coke and petroleum diesel yields. Crystallizable paraffins do not have a significant effect on the properties of the oils, the pour point of which does not depend explicitly on the composition.