The tachometer (2) displays the engine
speed in revolutions per minute (RPM). The beginning
of the red zone in the tachometer indicates
the maximum permissible engine speed for
all gears once the engine has been broken in. Before
reaching the red zone, you should shift into
the next higher gear, sel
Tires, Rolling Noises, General Information
Rolling noise perceived by the human ear is caused by
vibrations transmitted from the noise source to the ear via the
air.
Here we are interested in noises created by certain
characteristics of the tires as well as the effects of rolling
(noise source).