[jhein]

Thinking about either of these safety switches, either tach based or oil pressure based, when do the come into play? Basically, when the motor stops running. No tach signal means it's not running, no oil pressure means it's either not running or it will be stopping very soon. But how often in an accident does the engine stop running? Probably not if it's a rear or side impact. Maybe not even if it's a front impact, at least not immediately. And if you're running soft lines, then what is the likelihood they're going to fail in any case? So just how important are these devices?