Here is an excerpt from an advertisement from the 30s promoting Freewheel technology.
»(…) The freewheel car increases our feelings of well-being tenfold and, moreover, brings us savings. Thus, on the Paris-Marseille route, ie 800 km, a total of 220 km, corresponding to Paris-Avallon, can be coasted, engine at idle, without noticeable reduction in average speed. (…) "
