Anyone who has a calculator and has used that calculator to multiply amps X voltage from the motor plates of an electric motor on a compressor, and divided by 750 watts / horsepower, knows full well that all the manufacturers of public-consumption compressors are a pack of liars and thieves.
Anyone who is cynical about compressors is not surprised about real-air-tool air consumption as well.
To get the truth you have to measure it yourself. Otherwise you don't know what your variables are. A person practicing science writes three pages of set-up notes for 1/4 page of data. Common folk like most of us don't have the patience to do that, and when we tell somebody something, they should think seriously about where the truth lies in our statements. I include myself in the "common folk" category, and people in the High Fidelity and Air Compressor business as, as I have already stated, packs of liars and thieves, because they know better, and do it anyway.