Re: Survey about Braking...

["Khan M. Klatt" <kmk@pacificrim.net>]

On 5/4/98, you wrote:
>I've just got a bit to add - a question/comment:
>
>> That having been said, I think that it would be acceptable to downshift to
>> slow down when you're going too fast to efficiently slow down with the
>> brakes alone. For example, if you're coming off the freeway at 75mph, and
>> there's a backup right around the corner you didn't see, apply the brakes
>> with your right foot, and with your left foot, push in the clutch, shift
>> down, and slowly let out the clutch to add some torque related braking to
>> assist in slowing you down.
>
>I've always been under the impression that the brakes were capable of
>slowing you down as fast as your tires will manage - since they are
>capable of locking the wheels up.  With ABS I suppose it doesn't matter
>where the slowing force comes from, the brakes will reduce their drag if
>you lock a wheel.  Without ABS, I would think that using engine braking in
>a panic situation would tend to lock the two drive wheels, or cause the
>two non-drive wheels to not be braking at their maximum (this since the
>car comes with front to rear brake balance optimized for the car).  This
>logic would also seem to apply to using the handbrake to stop.
>
>But I could be wrong.  That's just what I've always thought...

What you say makes total sense.

What I mean by saying "efficiently slow down with the brakes alone" is that
to me and I believe other passengers in the car, (ASIDE FROM THE INITIAL
INERTIAL JERK ONCE YOU HAVE DOWNSHIFTED), downshifting and braking at the
same time allows me to slow down without having to STOMP on the brake, nor
to engage the ABS, to get me down to a stop.

When it is rarely used, downshifting can assist in applying smoothe
braking. One of my responsibilities to my passengers is to prevent any sort
of shock or surprise because I am paying attention and they are not. IMHO,
I think that downshifting and braking is less cause for concern for your
passenger who is daydreaming and not paying attention to traffic, than it
is to allow ABS or stomping on the brakes to allow you to stop.

All this is said from someone who has not taken any sort of meaningful
drivers or racing training courses, so don't take it as a matter of fact,
but a matter of opinion.

As Jeff Newton pointed out, using the handbrake in almost any situation to
stop from a driving position, is a bad idea because it will not offer you
any gains above and beyond what your brakes will already do anyway. At most
it will simply do what the ABS would have done, and at worst, it will cause
you to spin out (which is generally a bad thing because you lose control of
the car to avoid an accident).

I can summarize what I have to say by the two (maybe three) statements
(which may contradict each other depending on the situation):

1. To minimize wear and tear on your engine and other components, always
use your brakes to slow down-- do not ever downshift to slow down.

2. If using your brakes may engage ABS (on dry conditions), or will require
stomping on the brake, you might consider downshifting to assist in
braking. This should be done rarely, and only when you feel that your
normal brakes won't *comfortably* stop you quickly enough.

3. Avoid using your hand brake to stop you at all costs. It is the least
controllable way of stopping, and won't offer any benefits over braking
normally. That having been said, if your brakes fail for some reason, or if
you are the passenger, and the driver of the car passes out on you (heaven
forbid) you can attempt to stop by driving the wheel with one hand, and
SLOWLY and GRADUALLY applying the handbrake with the other hand until you
slowly drift to a stop (might work OK on a freeway with little traffic to
pull over to the side). (i.e. set the first notch of the handbrake at
60-35mph, the second notch from 35-5 mph, and the third notch from 5-0mph).
This should allow gradual and controlled stops from freeway speeds.

- -K