Automatic Transmission Drag Kills Stop and Go Gas Mileage

On virtually every automatic transmission car, while in stop and go
driving, it is necessary for the driver to ride the brake to keep the car
stationary or at speeds lower than approximately 10 mph.

This is because the transmission couples at idle speeds instead of going
into a neutral condition. This self propulsion occurs whenever the drive
range is selected, even though no pressure is applied to the gas pedal.

When the engine has to idle against this braking drag, the engine has to
work harder than if it were a no load idle. A byproduct of this
undesirable drag is increased fuel consumption as well as increased engine
and transmission heat. It might even cause a few accidents when the car
pulls into a slow car in front if the driver day dreams or his braking foot
gets too tired.

So why don't the automakers develop an automatic transmission that does not
pull the car when the engine idles and there is no pressure on the gas
pedal? I think its possible to do this because Toyota had a CVT
transmission that was perfect until testers complained it was too different
from regular hydraulic transmissions. So, Toyota made the CVT pull just
like all the others do. That proves Toyota is just as stupid as anybody
else in the business.

This is No. 27 of 1001 improvements desperately needed.

 

HERE WE GO AGAIN>>>>>>

 

Smarter drivers than you shift into neutral on long stops.
Your foot should still be on the brakes to keep you at the same location.

 

Like my father used to say, "Ideas are a dime a dozen."
Nomen's "ideas" are often born from ignorance of the details and
frustration in not being able to execute ideas in his personal life.
That's just my opinion.

 

Thats why new cars in a couple years will shut the engine off when your
stopped. The Hybrid Silverado was a testbed for this and it will be
incorporated into most models soon.

 

Oh God no.

 

Nomen Nescio wrote:


Sorry for feeding the troll, but I challenge anyone to design a tranny
control algorithm for re-engagement following the
complete-dropout-at-idle that can adequately handle *both* of the
following to the satisfaction of the consumer:
(1) A smooth start with light application of throttle for gradual old
lady takeoff from stopped,
*AND*
(2) A sudden pedal-to-the-floor start without effectively simulating a
high rev. neutral drop.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

(1) would be easy enough -- light throttle application would give a properly
designed torque converter (i.e., one designed for releasing into a
free-wheeling mode while stopped and for re-engaging smoothly) ample
opportunity to gently re-engage with nothing more than a light shift
sensation such as any other upshift sensation might create.

(2) would be easy with drive-by-wire. Giving the computer full control of
the vehicle lets the manufacturer design in behaviors they couldn't
otherwise. With the computer in full control of the throttle, the driver
flooring it from a standstill would cause the torque converter to re-engage
as quickly as it is designed to re-engage -- at whatever throttle opening
the computer deems reasonable -- followed by the computer ordering a rapid
opening of the throttle to fully open. With drive-by-wire, competent
programming and a competent transmission, this could be done amazingly fast.

I guess he had a more workable idea than you would have guessed...

 

Sorry, I believe that Ferrari VW, and Porsche already have this taken
care of (twin clutch manual/auto hybrids). I figure that if it's good
enough for a Porsche it might be good enough for a Taurus/Cavalier.

http://www.just-auto.com/features_detail.asp?art=1171
http://www.transmission-symposium.com/int/pressrelases.htm

But if Nomen Nescio has a suggestion, I'm sure that it'll be better
than this. Perhaps I'm reading yesterday's news.

 

Your solution for (2) would either give a slamming effect or cause a
perceptable delay in response. With the present system power train
slack already taken up and engaged, acceleration could start immediately
with no slam of engagement - quicker than the drive-by-wire. Maybe it
could be made "quick enough", but never quite as quick.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Check out the latest transmissions, Bill. Look at how smoothly
computer-controlled automatic-shifting manual transmissions engage the
clutch and shift. I've no doubt an automatic transmission's torque
converter can be similarly controlled to engage and disengage, even more
easily since it's got the benefit of hydraulics to dampen help smooth things
out.

We may never see such torque converters, though, if the automatic-shifting
manual transmissions start replacing traditional automatics entirely.

For example, check out the VW group's six-speed direct-shift gearbox in the
Audi A3, a hatchback sedan priced only in the $25,000-$30,000 range. This
transmission is also available in the VW Golf. You can click off
lightning-fast upshifts and downshifts with the F1-style paddles or let it
shift itself with smoothness that easily rivals an automatic.

Google "DSG" and you can read up on it. I found this quote: --"The
transmission also has a system that apes Formula 1 'launch control'. Keep
your left foot on the brake. Select 'Sport' mode on the transmission
quadrant. Switch off the ESP. Floor the throttle. The engine then revs to
3,200rpm, where it develops peak torque, but no more. All you have to do is
slide your left foot off the brake but keep the right fully planted and you
take off, redlining through all six gears if you have the space. But because
you have set off at comparatively low revs and because of the way the twin
wet clutches work, you could if you wanted to do this repeatedly without
straining or overheating the box."--

I bet that once you get a direct-shift gearbox you won't want any other
transmission -- why bother with a torque converter at all? Fortunately
we're seeing transmissions like these more and more due to the power and
efficiency benefits.

 

Your wrong there.

Agreed. Why, when a properly designed dry clutch and a fully manual
transmission is
superior in every way.

Of course, it takes skillful drivers to operate, which the majority of the
American public aren't - which is why we get stuck with the mess of
mechanical misconceptions like your VW transmission.

Fortunate if your a trans repair shop. For everyone else, the slight
savings in mileage will be offset by the cost to repair the things
when they break down, which will be often once they go past the
woefully short warranty period.

Ted

 

Thanks for that information - I wasn't aware of the TC-less "automatic"
transmissions.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Do you have the doom-and-gloom response about other technologies like
antilock brake systems, traction control, active suspension, etc.? I
imagine there were people having that reaction about disc brakes once upon a
time. For my part, I'll reserve judgement on their reliability until we see
statistics.

What *does* bother me a bit about all these new technologies is that they
require greater and greater control of the vehicle by the computer. How
long will it be before you start receiving traffic tickets in the mail
because your own car's computer notified the police department that you were
doing 78 in a 70 zone? Or how long before your car's computer refuses to
allow the vehicle to exceed the posted speed limit? Or how long before
police departments start using GPS data to send out speeding tickets, or
before the insurance companies increase your rate because GPS data indicates
you regularly exceed speed limits? That could all just be paranoia but it's
all easily conceivable given the revenue it represents for governments and
insurance companies and so forth.

Manual transmissions are great but they also require constant management by
the driver, which is why most people don't buy them. I love manual
transmissions but the two cars we own are automatics, partly because they're
both Durangos, but also because they're daily commuter vehicles and
passenger carriers where manual transmissions get a bit tedious. If I could
afford a third car as a fun/weekends kinda vehicle I'd get a manual.

 

Sure:

ABS: Does nothing but get you rear-ended. This has been thrashed out in
this
forum before. Yes- ABS will allow morons who don't know how to brake, get
the maximum stopping distance on ice, by just slamming down on the brakes.
No, it will not help when the guy behind you, who does not have ABS, cannot
match your rapid decelleration on ice and smashes into you. It makes it a
lot more expensive to service the brake system as you can't bleed air out
of it without a scan tool.

Note: I have ABS on 2 of my vehicles, BTW.

Traction Control: As has been pointed out before, the problem in snow and
low-traction driving environments is not getting going, it's stopping. TC
does
little to help this.

Note: I have all-wheel-drive on one of my vehicles.

Active suspension: Is the goal of the driving experience to drive a
plushmobile, or
is it to drive a vehicle that let's you have a bit of the road feel? This
is a personal
preference thing. I guess if your 70 and your bones ache at every jolt,
then you
will want this feature. Since it drives up the price, there should be
plenty of each
kind of vehicle available on the new and used markets for the forseeable
future
to satisfy everyone.

I imagine that's a pile of baloney. But, there are plenty of short people
rightly
upset about air bags, another safety improvement I guess you wholeheartedly
endorse.

Pray tell where are these? Please show me -current- reliability statistics
about
repairs on any used car device that was introduced a decade ago.

The auto industry really doesen't give shit on a shingle about used cars,
there
are very few reliability studies on costs to repair them, but there's a
whole lot
of "heard it through grapevine" advice out there.

Once the vehcile has passed out of warranty period, the only people that
care are
the people selling extended warranties, and when the vehicle has passed out
of
extended warranty period (often 100K) then not even those people care.

Keep in mind that if a vehicle model has terrible long-term repair costs,
the car
companies want to suppress that so that it doesen't reduce the resale value
of new cars (because a lot of new car buyers look at that data when choosing
new cars) and if a vehicle model has phenominally great long term
reliability
the car companies also want to suppress that so that people who would
otherwise
dispose of perfectly good used cars and buy new ones to replace them,
don't stop doing that.

The computer is far more reliable than any of the mechanicals that it is
set to controlling.

When that happens there will be plenty of people selling ticket defeaters
that
reprogram the computer to not do this. Not to mention that there's no
central
database of VIN-to-drivers out there.

Keep in mind that for a car computer to know it's own license number means
that when you put plates on a vehicle that your going to have to input the
license plate number. If your car has a police-informing computer in it,
you
just stick in a bogus plate number like EATME and the computer can only
tell the police that the car with plate number 'eatme' has violated the
speed
limit. Otherwise the computer only sends the VIN to the cops. That's fine
if your state can match up the owner and VIN number for the police, but
if the car is titled in another state? Suppose you decide to drive
cross-country?

And an even more interesting thing would be how is the car computer going
to know what speed zone your in to know you have violated the speed limit?
What if your driving in a state that has a 100Mph speed limit? Montana used
to
have no daytime speed limit, as a matter of fact.

I believe in every state, car insurance companies are very heavily regulated
by
the states as to what they are permitted to rate. Here in Oregon for
example
the insurance companies are only allowed to go back 3 years. You could have
committed vehicular homicide 4 years ago, drunk as a skunk, and if you keep
your nose clean for 3 years then your insurance rates are the same as
someone
with a clean 20 year record. Insurance companies are also not allowed to
rate by gender, even though their actuarial tables almost certainly show
fewer
accidents by women (fewer women get drunk as skunks then smash things
up) I think if such technology ever was developed you would see a huge
cry by constituients and the politicians would put the kibosh on such plans.

Keep in mind we already today have the technology to do this, but nobody
is proposing it.

It is surprising how you are focusing only on the negatives here. I for one
would
be perfectly happy with an alcohol sensor in the vehicle's air system that
when
it detected high concentration of alcohol, shut down the car. Such a system
would
certainly never be a problem for me, but it might keep you alive one of
these
days.

That is not why most people "don't buy them" Most people don't buy them
simply because most car models don't OFFER them.

This is a case where the car companies decided a long time ago that it was
cheaper to have just ONE kind of transmission in the vehicle, and so they
stopped offering stick shifts for most vehicles. Then when people didn't
buy
them, folks like you run around claiming that nobody must want them because
nobody is buying them, thus we shouldn't bother making them. Circular
logic.

I also suspect that the auto companies feel it's easier to meet CAFE when
shifting decisions are taken away from the driver and given to the computer.
People don't always decide to shift in the most fuel-efficient manner, y
know.

I drove a manual for 10 years as a daily commuter vehicle and never
had a problem. So did a lot of people. Your taking your own experiences
with them and trying to apply that to every other driver. The funny thing
is your post here seemed to start out chastising me for doing the same
thing.

I guess when it's my positive experiences with something (manual
transmissions) that is bullcrap, and when it's your positive experiences
with something (automatic transmissions) that you know best and I
should shut my hole?

Ted

 

See below.

DAS
--
For direct contact replace nospam with schmetterling
---

DAS: Not necessarily. I am pleased I have ABS on both our cars. And used
it (admittedly rarely, one tries to avoid the situations)
[...]

DAS: I have seen respected motorng journalists who like a good drive praise
traction control.

[...]But, there are plenty of short people

DAS: No. I am short and I applaud airbags. Led to a substantial reduction
in deaths and serious injury. Maybe the US should adopt the international
system where airbags and seatbelts complement each other. Unfortunately the
older of our cars does not have airbags.
[...]

For every safety innovation you can find a reason to be critical -- e.g.
seatbelts have led to an increase in whiplash injuries -- but we are looking
for overall improvements. I'd rather be whiplashed than dead.

 

You sure take offense where none is present, don't you?

Did you not read the entire message? I wasn't being negative about the new
technologies; I was pointing out a great new technology (direct-shift
gearboxes) and how it's only really made possible by giving the computer
direct control over throttle and other parts of the vehicle. I brought up
the other points only to illustrate potential pitfalls of letting the
computer have so much control, lest anyone like you think I'm in favor of
having computers take over the world.

Your comments on active suspension tell me you really have no clue what it
is? It's not something to make the ride more comfy -- it's to make the car
handle better. Look it up.

You think ABS is only good on ice? ABS helps on wet surfaces and other
situations. It'll even help in a hard emergency stop on dry pavement since
you can still get wheel lockup. It's not only for morons but also for
everyone else who has to slam on the brakes due to a moron running a stop
sign in front of them.

Traction control helps in dozens of situations. The weather might be warm
and dry, but when applying power pulling out onto the road from a parking
lot you might have one driven tire with good traction and the other driven
tire on a sandy spot on the road. Or it may just be a little rainy. In
lots of situations, traction control will get you going faster without a
tire spinning. If a car has ABS then traction control is very cheap for the
manufacturer to put on a car rather than than limited-slip differentials and
other technologies. When you have to merge into dense traffic and you have
a tire losing its grip, it's good to have anything you can get whether it's
traction control or anything else.

There are plenty of statistics showing what areas on a particular
make/model/year are problematic. Consumer Reports gathers such information
but there are plenty of others.

What percentage of people would go reprogramming their car's computer to
defeat features built in by the manufacturer, regardless of cause? You
might, I might, but the vast majority of average people wouldn't. It's
hardly risk-free, most people wouldn't know about or have access to
computer-reprogrammers, and many of them and wouldn't try them anyway.

No matter what state you live in, police from any other state can identify
who owns the VIN of your vehicle(s).

How am I applying my experiences regarding manual trannies to every other
driver? Did you not read my comment "I love manual transmissions"? Yet
manual transmissions are ordered at a dismally low percentage on many
vehicles, so manufacturers often end up dropping them from a model line.
Enough of them have to be ordered to make it worthwhile. Other options are
also dropped from a model line for much the same reason, along with many
other reasons, of course. The Mitsubishi Diamante was once a very high-tech
vehicle, but Mitsubishi dropped features like the rear-wheel-steering
feature in the later years because it was ordered in a very tiny percentage
of vehicles. Chrysler dropped AWD from the minivans, in part because it
gave them more room to implement their new Stow-n-Go, but also because it
was ordered in only a fraction of the total orders.

- - - - -

 

You said:

I said:

You said:

My comments about the fancier transmissions being more expensive to repair
were NOT gloom and doom, and I resented you claiming that they were.

Increasing the complexity of anything makes it more expensive to repair,
and more prone to break down. Your pushing a transmission here that
adds 2 extra gears, plus the ability for the driver to "click off
lightning-fast upshifts and downshifts with the F1-style paddles" and
on top of it this is a VW product and their current quality control sucks.

And you are claiming increased repair bills are a gloom-and-doom scenario?
Pahgh!

In any case, the other items were the gloom-and-doom scenarios you
requested - but I didn't say I agreed completely with them. You wanted
to know the cons to those technologies, you didn't indicate you wanted to
debate them until your response here.

No, that was an example only. Of course, ABS works in other scenarios -
if you define "works" as "the ABS computer triggers it" not "works" as
"saves you from a collision"

Do you regularly slam on the brakes? I don't - usually though because
I tend to carry a lot of stuff around on a regular basis, and I don't enjoy
computer parts, my laptop, paperwork, and such all sliding off the seats
into a jumbled mess on the floor. I have learned some good driving
techniques that allows me to avoid getting into most of those situations,
and the few times that I do slam on the brakes it is when I'm going
under 5Mph. (and yes, the shit all slides off the seats onto the floor)

Take your stop sign example. Yes, most people just drive through
uncontrolled intersections with the stops against the cross traffic,
blithly oblivious to the world. I do not. If I'm approaching an
intersection with a car coming at right angles to where we would
hit the intersection at the same time, I always start slowing even
when I don't have a stop sign and he does, until I see him slowing.
Then I let up on the brake but don't take my foot off it until I'm
through the intersection.

Or take another example of a major throughfare and someone
pulling out into traffic unexpectedly. I don't have this problem
happen to me because as soon as I get on the throughfare I move
to the center lane. I don't tool down the street in the right lane,
I only get into it when I'm ready to turn off the intersection.

If it's a street with a single lane both directions, if I see a car
waiting to pull into traffic I take my foot off the gas and on to the
brake and let my car start coasting, until I see that he's not
moving.

Of course, there are blind intersection scenarios and other fringe
scenarios you can cite that ABS might do some good. Not
common, though.

Why is the goal to get going into the road super fast? Once more this is
a very rare intersection. I can think of only 1 in the entire city here
that is
like this, and probably 1,000 cars a day use it, there is no sandy spots on
it.

Most dense traffic situations the road your on is going to be densely
traveled also, and any sand on it will have been long ago beaten off.
This is a contrived situation that is not common. And once your in
the dense road, you can gas it.

No, they would just go to the hole-in-the-wall places that today specialize
in getting polluting vehicles to cheat the emissions inspection, and those
places
would swap in a complete new refurb computer, then give them their old one
in case they ever sell the car.

People pay more than that for radar detectors.

And if the owner claims they were not driving the vehicle? What then?
That is why the photo radar people take the drivers pictures, they can
match them against the drivers license if there's a dispute.

You are claiming that manual transmissions "get a bit tedious" on passenger
vehicles. Which is your personal preference, it is not a property of the
manual transmission. You also claim that most people don't buy them
because they require attention from the driver. Once again this is a
personal preference thing - they might require too much attention from you.

Once again, this is deliberate by the manufacturer. They start out with a
model line where you can go to the dealer and see both manual and
automatic, and the manuals are a bit cheaper. Then they jack up the price
of the manual and the automatic so they are the same. Then the next year
they drop the manual and it's now an orderable option, and you have to
wait to get your car with it. Then the next year they tack $1000 onto the
price of this option so now purchasers have to wait, plus pay a premium.
Then they drop the manual completely, claiming there's no demand for it.

Ted

 

As an automatic fan (something I began to appreciate as I grew up...) I wish
we did not have to pay vast premiums for automatic gearboxes in Euope.

DAS

 

What is a typical cost for an automatic in Europe? The premium here in
the USA is typically $800-$1200. I prefer standard shift myself and
find it nearly impossible to find them as few dealerships are willing to
stock them. I don't think manuals account for even 10% of auto sales in
the US these days.


Matt