On 2014-10-31 12:02:41 +0000, David Cantrell said:

On Thu, Oct 30, 2014 at 06:04:13PM +0000, Neil Williams wrote:

4WD of course does both, but it isn't viable to fit that to all cars,
nor is it necessary.

I beg to differ. I couldn't have got out of the car park at Glyndebourne
last week without it!

You think it is worth the extra cost on every car? Really?

Neil
--
Neil Williams
Put my first name before the @ to reply.

On Fri, 31 Oct 2014 12:16:09 +0000
Roland Perry wrote:
In message , at 11:33:19 on Fri, 31
Oct 2014, Neil Williams remarked:
It's a sort of "minimum speed cruise control" using ABS. I'm sure it
helps the same sort of driver who invokes ABS on a 2WD car.

You might as well "invoke ABS" if you're wanting to stop quickly and
without loss of control - as it, unlike you, can control each wheel's
braking separately, it will do it better than you will. If you need an
emergency stop, foot hard on the brake, concentrate on steering and let
ABS do its thing, disconcerting though it may sometimes be.

There are some conditions where I might indeed find myself in a pickle
where ABS is invoked, but it doesn't happen very often. Something like
once every five years.

ABS in the snow is a PITA and in some instances dangerous as you can have
your foot mashed to the floor with no sign of the car slowing at all.
Whereas if the wheels lock in snow they tend to build up a wall of snow
in front of them which then slows the car.

--
Spud

On Fri, 31 Oct 2014 12:27:23 +0000 (UTC)
Recliner wrote:
All tyre designs are compromises. They have to balance grip, wear
resistance, temperatures at high speeds, etc. A grippy all-weather tyre
won't last as long as one designed for long life, and neither will perform
well at 150mph. The most extreme example is slick racing tyres, which are
wonderfully grippy and perform well at high speeds, but instantly aquaplane
with even gentle rain; wet weather racing tyres are OK in moderate rain,
but fall apart at high speeds in the dry. Road tyres are less extreme in
their characteristics, but are still tuned for different conditions.

I think one of the main reasons a lot of high performance cars are limited
to 155mph is down to the tyres. The manufacturer doesn't want to have to
supply 200mph+ capable tyres for road cars that will almost never reach that
speed even in germany.

But of course if they didn't limit the cars they would have to supply the
correct tyres because there's always 1 **** in a million who'd try to max it
and end up upside down - or dead - after a blowout and either him or his
relatives would sue the car manufacturer.

--
Spud

In message , at 12:21:50 on Sat, 1 Nov
2014, d remarked:
It's a sort of "minimum speed cruise control" using ABS. I'm sure it

helps the same sort of driver who invokes ABS on a 2WD car.



You might as well "invoke ABS" if you're wanting to stop quickly and

without loss of control - as it, unlike you, can control each wheel's

braking separately, it will do it better than you will. If you need an

emergency stop, foot hard on the brake, concentrate on steering and let

ABS do its thing, disconcerting though it may sometimes be.



There are some conditions where I might indeed find myself in a pickle

where ABS is invoked, but it doesn't happen very often. Something like

once every five years.



ABS in the snow is a PITA and in some instances dangerous as you can have

your foot mashed to the floor with no sign of the car slowing at all.

Whereas if the wheels lock in snow they tend to build up a wall of snow

in front of them which then slows the car.


There's some truth in that. I've had ABS kick in only on wet/icy roads
though, and at low speeds (less than 20mph).
--
Roland Perry

On 2014-11-01 12:21:50 +0000, d said:

ABS in the snow is a PITA and in some instances dangerous as you can have
your foot mashed to the floor with no sign of the car slowing at all.
Whereas if the wheels lock in snow they tend to build up a wall of snow
in front of them which then slows the car.

That, and sometimes in ice/snow you want to stop as a priority with
less concern about which way you are facing when you do. But for most
use-cases (particularly those at higher speeds where lives are at risk
rather than just minor vehicle damage) ABS wins out.

Neil
--
Neil Williams
Put my first name before the @ to reply.

On 30/10/2014 18:04, Neil Williams wrote:

On 2014-10-30 15:59:12 +0000, Roland Perry said:

FWD is better to begin with in light snow/ice, but once conditions
have deteriorated sufficiently I'm sure that RWD is better.

I doubt it. The problem with RWD is that once things start to slip you
lose steering, and the back end just fishtails. Whereas any grip a FWD
car can get pulls it in the desired direction.

4WD of course does both, but it isn't viable to fit that to all cars,
nor is it necessary. I have no need for a 4 wheel drive car - on the
week or so in a year if that when things get treacherous, I'll work from
home and leave the car on the drive, and do other local travel on foot
or in other peoples' vehicles, i.e. buses and taxis where still
running. And of course use the train to do long-distance travel, as
despite what people say about it in very bad conditions it usually gets
through when being on the roads is seriously ill-advised.

Given this is utl, I feel compelled to point out that the latter comment
is a rather 'north of the river' centric one - third-rail railways and
snow aren't a great combination!

On Fri, Oct 31, 2014 at 10:30:44AM +0000, Roland Perry wrote:

The other issue is that a 4WD vehicle doesn't need to brake at every
corner, like a pathologically understeering FWD car might, so
powering-round can be just as good a way to avoid the ditch.

No car needs to brake at every corner. That's just the driver being a
tit.

I wish I could remember what book it was that I read once. I think it
was by Stirling Moss, on driving efficiently and safely on the road. He
pointed out that using the brakes a lot means that you're burning more
fuel than you need to (because the purpose of brakes is to turn kinetic
energy into waste heat), and unless you're very precise with your
braking you're actually making your journey take longer because you burn
off too much KE.

I'm not entirely convinced by the second point, but the first is
certainly true.

--
David Cantrell | A machine for turning tea into grumpiness

The voices said it's a good day to clean my weapons

On Fri, Oct 31, 2014 at 12:14:32PM +0000, Recliner wrote:
David Cantrell wrote:
On Thu, Oct 30, 2014 at 06:04:13PM +0000, Neil Williams wrote:
4WD of course does both, but it isn't viable to fit that to all cars,
nor is it necessary.
I beg to differ. I couldn't have got out of the car park at Glyndebourne
last week without it!
Soft mud?

Wet grass on soft ground on a steep slope.

--
David Cantrell | Minister for Arbitrary Justice

Nuke a disabled unborn gay baby whale for JESUS!

On Fri, Oct 31, 2014 at 12:37:08PM +0000, Neil Williams wrote:
On 2014-10-31 12:02:41 +0000, David Cantrell said:
On Thu, Oct 30, 2014 at 06:04:13PM +0000, Neil Williams wrote:
4WD of course does both, but it isn't viable to fit that to all cars,
nor is it necessary.
I beg to differ. I couldn't have got out of the car park at Glyndebourne
last week without it!
You think it is worth the extra cost on every car? Really?

My apologies for not pointing out the humourous intent behind my
message. I didn't think it was necessary. I forgot that this was the
internet.

--
David Cantrell | A machine for turning tea into grumpiness

PERL: Politely Expressed Racoon Love

In message , at 12:29:52
on Mon, 3 Nov 2014, David Cantrell remarked:
The other issue is that a 4WD vehicle doesn't need to brake at every
corner, like a pathologically understeering FWD car might, so
powering-round can be just as good a way to avoid the ditch.

No car needs to brake at every corner.

There's an implied "where the car needs to be slowed down" after
"corner".

Perhaps some people can drive such that they approach every corner
having engine-braked (let's avoid discussing how effective that is on a
slippery road) sufficiently to be able to make it round without needing
to touch the brakes, but that's probably a recipe for a very slow trip
and might even be impossible downhill.
--
Roland Perry