There used to be (may still be) a guy in Austin, Tx who for a couple thousand bucks will show up to court with a big suitcase of evidence, and thouroughly convince the jury that breathalyzers are crap.
A .08 blood-alcohol level is pretty relative to the person drinkning. Some folks will be stoned at that level and others won’t even be buzzing. Me personally, I am buzzing happily at .08 but would not consider myself to drunk to drive. If you’re interested in playing with breathalyzer for a day check wih your local police/sheriffs. There are a couple programs where you basically go to class on breathalyzers then spend a few hours drinking and bullshitting with the cops. You get to test the breathalyzer evey hour or so and see how many drinks vs. time gets you to the legal limit.