Comment by AngryData

That is definitely something to watch out for with cars from the 50s to early 70s. Often the studs will just snap and not bend the wrench though, which is fine since it is better to just replace them with right hand threaded studs.

I believe the idea back in the day was so lug nuts would want to screw themselves tighter if they were loose whenever you braked as a safety feature so the wheels don't fall off. In practice it isn't really effective at unless you are doing some crazy hard braking like in a race but they should never be anywhere near loose enough to start with for such a minor force to screw or unscrew them. Your wheels aren't really suppose to be holding you up through the shear force across the studs, but held by the clamping force friction between the wheel and the wheel hub.