On 24/08/16 11:26, NY wrote:
"Dave Plowman (News)" wrote in message
...
In article ,
NY wrote:
It must be good to feel smooth, fairly constant acceleration, without
pauses in acceleration while the transmission (auto or manual) changes
gear.

No reason to have a pause in acceleration while an auto changes gear.

All the automatics I've driven have given a noticeable lurch (due to
momentary disruption of power to wheels) when they change gear under
hard acceleration, even if the change is undetectable under gentle
acceleration.

There is also the problem that the rate of acceleration decreases with
each upward change of gear (lower mechanical advantage of higher gear
lead to lower torque at wheels). In a manual car you adjust for this: as
you change up you apply slightly more accelerator pressure than you
would in the lower gear, even allowing for the accelerator not needing
to be pressed as far because the engine speed is lower - when you are
learning to drive you learn to make the adjustment sub-consciously. But
in an automatic further pressure on the accelerator to maintain the same
acceleration can occasionally cause the gearbox to shift back down to
the gear it used to be in: I always have this problem as I accelerate
out of a roundabout and end up "see-sawing" between high acceleration in
lower gear or less acceleration in next gear up. I end up thinking
"you've changed up into third, now *stay* in third and let me accelerate
in that gear".

Spend more time working out the box's algorithms.



--
A lie can travel halfway around the world while the truth is putting on
its shoes.