Driving Through Water - BMW 2007 M3 Owner's Manual

Hydroplaning
When driving on wet or slushy roads,
reduce road speed. If you do not, a wedge
of water can form between tires and road sur-
face. This situation, known as hydroplaning,
means that the tire can completely lose contact
with the road surface, so that neither the car can
be steered nor the brake be properly
The risk of hydroplaning increases with declin-
ing tread depth on the tires, refer also to Mini-
mum tread depth on page 199.

Driving through water

Drive through water on the road only if it is
not deeper than 1 ft/30 cm, and then only
at walking speed at the most. Otherwise, the
vehicle's engine, the electrical systems and the
transmission may be damaged.<
Use the parking brake on inclines
On inclines, do not hold the vehicle for a
lengthy period using the clutch; use the
parking brake instead. Otherwise greater clutch
wear will result.<
For more information about the drive-off assis-
tant, refer to page 78.
Braking safely
Your BMW is equipped with ABS as a standard
feature. Applying the brakes fully is the most
effective way of braking in situations in which
this is necessary. Since the vehicle maintains
steering responsiveness, you can still avoid
possible obstacles with a minimum of steering
effort.
Pulsation of the brake pedal, combined with
sounds from the hydraulic circuits, indicate that
ABS is in its active mode.
Driving in wet conditions
When roads are wet or there is heavy rain,
briefly exert gentle pressure on the brake pedal
every few miles. Monitor traffic conditions to
ensure that this maneuver does not endanger
other road users. The heat generated in this
process helps dry the pads and rotors to ensure
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that full braking efficiency will then be available
when you need it.
Hills
To prevent overheating and the resulting
reduced efficiency of the brake system,
drive long or steep downhill gradients in the
applied.< gear in which the least braking is required. Even
light but consistent brake pressure can lead to
high temperatures, brake wear and possibly
even brake
You can increase the engine's braking effect by
shifting down, all the way to first gear if neces-
sary. This strategy helps you avoid placing
excessive loads on the brake system.
Never drive with the clutch held down,
with the transmission in idle or with the
engine switched off; otherwise, engine braking
action will not be present or there will be no
power assistance to the brakes or steering.
Never allow floor mats, carpets or any other
objects to protrude into the area around the
pedals, otherwise pedal function could be
impaired.<
Corrosion on brake rotors
When the vehicle is driven only occasionally,
during extended periods when the vehicle is not
used at all, and in operating conditions where
brake applications are less frequent, there is an
increased tendency for corrosion to form on
rotors, while contaminants accumulate on the
brake pads. This occurs because the minimum
pressure which must be exerted by the pads
during brake applications to clean the rotors is
not reached.
This can also lead to a permanent loss in ride
comfort and to squealing noises during braking.
A loss in comfort can also be caused by
extended braking with little pressure on the
pedal.
Should corrosion form on the brake rotors, the
brakes will tend to respond with a pulsating
effect that even extended application will fail to
cure.
For information on brake system technology,
refer to Compound brake on page 109.
failure.<