My wife getting scared

BDS writes:

"or something"?

I presume there are multiple ways to simulate engine failure, depending on how
much realism one is prepared to sacrifice.

How is it different?

The engine hasn't actually failed, and in particular an idling engine is very
different from a stopped engine.

Why does this require a full-motion sim?

It doesn't, but many people here believe that anything that isn't moving isn't
realistic.