Why do buses seem to vibrate when they are stopped, but they don't vibrate when they are moving?

Question

Why do buses seem to vibrate when they are stopped, but they don't vibrate when they are moving?

Answer 1

Thats a really good question, maybe when their idling it vibrates and when your in the bus you dont notice it cause of all the potholes lol, I reckon this one deserves a star!

Answer 2

Most transit buses use Detroit Diesel Series 50 engines which are only 4 cylinders and are designed to cycle low while idling for more than about 7 seconds. It is for efficiency since buses spend so much time idling.

Answer 3

The engine runs smoother when not at idle (around 1000 rpm).

Answer 4

It's the vibration from the engine idling.  When it's moving, the engine is running at a much higher speed, and doesn't vibrate.  

What Roaddog said above is GREAT!  :D

~Cindy!  :)

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