Methodology is an Internet review of related facts.
Findings: Jet engine schematics are available online and can be interpreted to find the number of bearings. Values for the CFM56 engine are 5 bearings with 3 of them upstream of the bleed port. Oil consumption should be assumed to be 0.3 L/h for the CFM56 engine. Rates for selected other engines are also given.
Research limitations are due to the fact that detailed company data is not available and own measurements can not be made on passenger jets.