"Friction losses" refers to the energy or power that is lost due to the resistance encountered when two objects or surfaces rub against each other. It is the energy that gets wasted in overcoming this resistance or friction. Full definition
This enables a smaller and lighter cooling fan on the back of the radiator and reduces friction loss by approximately 30 %. (greencarcongress.com)
How can you get better engine efficiency or better mileage with a CVT with more transmission friction loss than dual clutch units? (greencarcongress.com)
This also limits the maximum RPM of the engine because there are increased friction losses due to increased speed of the piston at the same RPM when compared to an engine with less stroke. (mechanics.stackexchange.com)