Re: What happened when we rev-up the engine?

There may be some merit in revving-up the engine a little when starting 
cold and before shifting into gear. Some cars tend to die if a load is put 
on a cold engine at idle speed.  Also mechanics and race car drivers might 
want to listen to the engine at a higher speed to see if they can hear 
something that they wouldn't hear if idling.  Apart from this, the only 
purpose of revving up the engine seems to be the satisfaction of listening 
to it.  It's the sound and feel of a powerful beast ready to spring into 
action.  I think you'll find that most on the revving up comes from males 
in powerful - or noisy - vehicles.

Vroooom - vroooom.