"Dave Plowman (News)" wrote in message
...
In article ,
NY wrote:
All of the automatic cars that I have driven in the 1980s to early 2000s
(my dad's Citroen GS with C-Matic manual-torque-converter transmission,
his Ford Sierra and Honda Accords, and various Fords and Vauxhalls that
I've been loaned) have exhibited the same behaviour. With the car
stationary on level ground and no brake on (eg just released footbrake)
you apply power gradually and suddenly there is a bit of a lurch as the
car starts to move, akin to letting a manual clutch in a bit too
smartly. Most of these were at least 15 years ago, but the most recent
auto that I drove was a Japanese car (I forget what, not not a Honda)
which was probably a few years old when I drove it a couple of years ago.

Very odd. Most autos will move off on a level road with no throttle
applied. Called creep.

Hmm. I'd forgotten about creep. I wonder if it was that the transition from
creep to normal running was jerky, rather than the transition from
stationary to creep. There was certainly something about all of them which
made it difficult to accelerate smoothly from rest to (for example) 30 mph,
without a jump, either from when the car was stationary or else from when it
was creeping very slowly. I presume a dodgy transition from 1st to 2nd would
cause the symptom, though you'd expect it to be at a fairly high speed (eg
faster than walking pace) whereas my vague memory of it was that it happened
at a lower speed.

I would have been used to driving a manual car by the time I first drove one
of my dad's automatics (probably the C-Matic Citroen): being a company car
(*), they wouldn't let me drive the car till I'd passed the test. So
anything which had to be driven differently from a manual in terms of how
you applied power (apart, obviously, from having no clutch and not needing
to change gear) would have been very noticeable. But that doesn't explain
the problem with later cars: by then I'd have been used to driving a variety
of manuals (as opposed just to the car I'd learned on) and the technology
would be more recent.

That C-Matic was a really nasty transmission. It had a gear layout like a
3-speed manual, with reverse and 1st in one vertical plane and 2nd and 3rd
in another plane, and the movement of the gear lever was very notchy and
noisy. As far as I know it was a normal torque-converter planetary-gear
automatic, except with manual control of the gear-selection (ie the
tightening and releasing of the band brakes) instead of automatic
electro-mechanical or electronic logic choice and servo-selection of the
gears.



(*) When my sister was learning to drive a few years after me, Dad told her
that it was a company rule that before sons or daughters of employees were
allowed to drive a company car, they had to have an interview and
demonstration drive with the very taciturn, humourless and irascible CEO of
the company to make sure they were trustworthy and responsible. I backed up
Dad's story and made up a scare story about what an ordeal my "interview"
had been. She believed us - until several weeks later when Dad couldn't keep
a straight face any longer. She called us both *******s - and rightly so ;-)