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Default Does a tyre change its CIRCUMFERENCE when underinflated?

"Rod Speed" wrote in message
...
How easily do people find it is to control the speed accurately at very
slow speed (eg when manoeuvring or when crawling forward in a queue of
traffic).


Do you do that much ? We dont see much of that here, just a bit
of stop start moving while waiting for the lights to change at times.


Parking (at home and in car parks and on side of road). Moving slowly in
traffic jams (when I can't avoid them).

It may be that I've never developed the muscle memory to be able to
control a car's speed solely on the accelerator, when in a manual car I
tend to control the speed also with the clutch, with a more constant
engine speed.


That certainly explains why you have had to replace clutches a
lot more than I have ever needed to. I have have never had to
ever replace one in will over half a century of driving every day.


What is a good life for a clutch? My earlier cars needed new clutches at
about 70,000 miles. My present car has done 170,000 and is still on its
original clutch - unless the clutch was replaced within the first 18,000 of
its life before I bought the car. The bite point has got gradually higher,
but I can't detect any slippage, even with the handbrake on and trying to
set off in third. I'd say that 170,000 miles is a good life for a clutch.

For me, the best combination would be a DSG that had a clutch pedal that
was only used for finer control of speed for very slow manoeuvring and
which was not used for gear changes.


IMO it makes more sense for the automatic to be able to do that auto.


As long as it is capable of very gradual takeup of power for inching
forwards. I've found with some, you increase the revs, initially nothing
happens and then the clutch kicks in and the car moves faster that you were
expecting so you immediately come off the power (and maybe even brake) to
compensate. On the level the car may creep forward at idling speed with your
foot off the brake, but when going uphill you need a bit of accelerator and
get the sudden kick-in.

With a (conventional) automatic, I'm always scared stiff, especially if
the accelerator pedal/linkage sticks slightly as the car gets older, of
the accelerator pedal moving suddenly and the car surging forwards.


Never had that happen and the obvious way to avoid that is to design the
accelerator so that can never happen. Shouldnt be hard to ensure that.


Yes I wonder why cars still have a Bowden cable to a sensor under the
bonnet, when nowadays the sensor could be right next to the pedal,
eliminating the friction of the Bowden cable.

When I have driven automatics occasionally (eg as hire cars on business
journeys) I've been very aware of this possibility when reversing out of
a parking space and the need to release the accelerator and/or touch the
footbrake the instant that I detect it happening


IMO with an automatic it makes more sense to have one foot on
the brake and one on the accelerator and just brake as required.

- a reflex which I bet elderly drivers who drive into shop fronts haven't
got.


With those the problem appears to just be they press the accelerator
instead of the brake.


It may be a bit of both: maybe (and I'm speculating) they press the
accelerator a bit too hard, panic when the car surges forwards unexpectedly,
and hit the accelerator harder instead of taking their foot off the
accelerator and hitting the brake.


It's the only time that I left-foot-brake: as a precaution when inching
forwards/backwards in a car with no manual clutch.


No reason not to do it routinely when parking so you can
always brake when required, even if its some kid running
in front of or behind the car etc.


I think the normal reason for not using left foot braking, especially if you
are used to driving a manual car and only occasionally drive an automatic,
is that the left leg tends to be used to large movements for operating the
clutch, whereas the right leg is used to finer movements for operating brake
and accelerator. If you brake with your left foot you may subconsciously
press far too hard. Also, it avoids pressing brake and accelerator at the
same time, and stressing the gearbox - for those gearboxes which don't
disengage the drive when the brake pedal is pressed, to avoid this.