^Trusting the manufacturers, indeed. :icon_wink
Really wide tire on a skinny rim will cause terrible handling (the wider, the worse it gets), safety issues with a massive flexing sidewall and, IMHO, looks stupid as hell.
Really skinny tires on a wide rim (AKA Drifter tires
), Will, also cause a flattened sidewall, but will curve in so there will be less tire touching the ground.
Either way, going one way or the other too much is only going to hurt your tires and your wallet.