On Tue, 05 Jul 2005 08:39:12 GMT, Alan Baker >
was understood to have stated the following:

>In article >,
> "David W. Poole, Jr." > wrote:
>
>> On Tue, 05 Jul 2005 07:10:48 GMT, Alan Baker >
>> was understood to have stated the following:
>>
>> >> >Gearing down would *not* have helped. Think about it: your brakes have
>> >> >the ability to completely lock the wheels, so how would shifting into a
>> >> >lower gear have done anything except distract you from the business of
>> >> >getting stopped as quickly as possible with the system in your car
>> >> >specifically designed for that purpose (the brakes)?
>> >>
>> >> Surely you're not serious? Locking the wheels will provide for better
>> >> control of the vehicle than free-wheeling wheels? Uh, why do they put
>> >> ABS on cars now?
>> >
>> >Read what I said and not what you think I said.
>>
>> Clarification noted.
>>
>> >The brakes are *capable* of locking the wheels, ergo they can provide
>> >all the necessary stopping force and engine braking isn't necessary.
>>
>> In the case of the OP, his wheels locked for 100 feet. That was 100
>> feet he wasn't doing the job of stopping his vehicle as fast as
>> possible. It's also 100 feet that, if he would have had to turn his
>> steering wheel, he may have lost even more control.
>
>People overestimate the difference between optimal braking and locked
>tires. Chances are very good that if he'd been trying to modulate
>braking force to keep the wheels at the threshold of adhesion he'd have
>been less effective at it than is necessary to exceed the deceleration
>of fully locked braking.
>
>Although if he really did lock the brakes, it explains why he kept going
>straight ahead.

Which may have been a bad thing, had he needed to turn.

>> >None of that means that I think locking the wheels is a good idea. It
>> >can be in certain circumstances, but that's another discussion. <g>
>>
>> I understand now.
>>
>> I'm just thankful that I've had the opportunity to drive a manual
>> transmission and learn how to use the engine for deacceleration; there
>> have been times such engine braking has gotten me through situations
>> where foot brakes probably would have cost me, particularly when water
>> or other substances contribute to the asphalt's coefficient of
>> friction.
>
>There's no magic to engine braking and if you have a typical two-wheel
>drive vehicle, it's only operating on half the available contact patches.

If it's a rear wheel drive, at least the front wheels are left to
their main purpose of steering.

>Use engine braking for speed control on long hills? sure. It keeps the
>brakes from overheating.
>
>But use engine braking for panic situations? No. No way.

Perhaps not, at least under dry circumstances. But if the roads get
slick, I would rather not hit the brakes any more than necessary.

As always, YMMV. :-D


--

The last song I started on my PC was: Linkin Park - Opening - Reanimation
K:\Audio\Linkin Park\Reanimation\01 - Opening.mp3
This is track 30 of 457 in the current playlist.