<dold@XReXXItXsX.usenet.us.com> wrote in message
news:d22ufi$1t9$2@blue.rahul.net...
> In rec.autos.makers.honda Michael Pardee <michaeltnull@cybertrails.com>
> wrote:
>> Reverse is MG2 all the way.
>
> I had heard that. But at stall, that's 94 HP, isn't it? I've heard of
> people getting stuck in potholes, because they couldn't move forward and
> didn't have the power to move backward. I was trying to decide how I
> could
> test for that.
>

As with all cars, it's zero hp at stall (any force times zero distance).
However, the full electric torque is available. The torque is considerable -
295 ft-lb compared with the rated 82 ft-lb from the engine - so the stories
of getting stuck in potholes are urban legend. (But note the torques aren't
directly comparable because of the effect of the power split device... the
electric provides something like 2/3 of the torque at the wheels.) At any
rate, I can attest from our 40K miles experience with a 2002 model it just
isn't a problem.

>> At full output, a significant part of the engine power is channeled
>> through
>> MG1 to MG2. That part limits the power of the system because the power
>> can
>> only be counted once. For example, if you have a 100 hp engine and a 50
>> hp
>> motor, but at full power 20 hp of the motor output comes from the engine
>> through MG1 (rather than from the battery) the total is only 130 hp.
>
> I've heard that this power arrangement, where MG1 is draining power during
> highest power demand, is due in part to the battery not having enough of
> an
> amperage rating to drive MG2 at full power, but I wonder about that.
> Maybe
> it just isn't efficeient to run at full power from the batteries for very
> long, due to the total amp-hours available, and a balance has been
> found that is more efficient.
>
This is something I have trouble getting my mind around. The bottom line is
that the hybrid computer gets the command from the accelerator and brake
pedals to go so much or stop so much, and it calls on the engine or
batteries to make it happen according to the hybrid computer's programing.
For example, in the earlier generation if more than 9 KW was needed the
engine would fire up. In the current generation it is some slightly higher
figure I don't remember.

As far as the generation by MG1, it is easiest to think of it as the way it
provides the prescribed load to the engine. That's how the "ECVT" does it
thing.

It certainly illustrates why the "ECVT" can't be replaced by a manual
transmission. The engine is a resource of the hybrid computer and is only
under the most indirect control of the driver... about the way your heart
rate is under your control. I can floor the accelerator with the shifter in
"park" and hold it there. The engine gradually revs, reaching a peak of 2250
rpm in a couple of minutes. Imagine trying to shift that arrangement.

Mike

 

In rec.autos.makers.honda Kevin McMurtrie <mcmurtri@dslextreme.com> wrote:
> How much does the balancer weigh? The 05 Accord Hybrid engine seems to
> rev up slowly compared to my simple old 97 Civic HX. It's the one thing
> that disappoints me a little - major downshift lag when stepping on the
> gas. It makes me miss a 5 speed manual.

I don't think it would affect the balancer at all. On the other hand,
there wouldn't be a flywheel, since the IMA is effectively the flywheel.
That would help smoothness at idle.

Engine RPM when blipping the throttle could be part "drive by wire".
There's a lot of computerized engine control involved. The Civic still has
a throttle cable. I don't know about the Accord. The Ford Escape does
not. In the Ford, blipping the throttle does absolutley nothing unless you
go beyond about 2/3 throttle, at which point the RPM climbs rather slowly,
maybe 2 seconds to 3000 RPM.

It could also be the heavy flywheel affect of the IMA.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

 

In rec.autos.makers.honda Kevin McMurtrie <mcmurtri@dslextreme.com> wrote:
> But the Accord Hybrid is rather different. As far as I can tell, the
> electric motor is to keep the engine running smoothly when it's
> switching in and out of gas saving modes. The power meter shows little
> activity and the 15 HP electric motor is tiny compared to the 240 HP gas
> motor.

It seems to be exactly the same as the Civic, almost the same as the
original Insight, and completely different from the Prius and Escape.

The point about the motor being tiny is true, though. The benefit from
idle-stop is still there, as is the cleanliness of the engine at initial
takeoff, where the ICE wouldn't normally be very efficient.
The Accord IMA produces 12% more hp than the Civic.


---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

 

In article <mcmurtri-8ECFCE.21251027032005@corp-radius.supernews.com>, Kevin McMurtrie <mcmurtri@dslextreme.com> wrote:

>But the Accord Hybrid is rather different. As far as I can tell, the
>electric motor is to keep the engine running smoothly when it's
>switching in and out of gas saving modes. The power meter shows little
>activity and the 15 HP electric motor is tiny compared to the 240 HP gas
>motor.

True, but note that the vast majority of the time (or at least on
the wimpy EPA certification cycles!) very little of that 240 hp is
actually used. To be sure, the Accord is a lot heavier and less
aerodynamic than the Insight. So it would benefit from a bigger
battery. But (as you no doubt know) the proportion of battery to
ICE size doesn't need stay the same as ICE power goes ballistic.

 

In article <1uOdnSJQxtSULNrfRVn-iQ@comcast.com>,
SoCalMike <mikein562athotmail@hotmail.com> wrote:

> Kevin McMurtrie wrote:
> > But the Accord Hybrid is rather different. As far as I can tell, the
> > electric motor is to keep the engine running smoothly when it's
> > switching in and out of gas saving modes. The power meter shows little
> > activity and the 15 HP electric motor is tiny compared to the 240 HP gas
> > motor.
>
> thats kinda cool. i wonder if they can use that in place of balance shafts?

It's probably technically possible but I bet it would eat a lot of power.

How much does the balancer weigh? The 05 Accord Hybrid engine seems to
rev up slowly compared to my simple old 97 Civic HX. It's the one thing
that disappoints me a little - major downshift lag when stepping on the
gas. It makes me miss a 5 speed manual.

 

Kevin McMurtrie wrote:
> But the Accord Hybrid is rather different. As far as I can tell, the
> electric motor is to keep the engine running smoothly when it's
> switching in and out of gas saving modes. The power meter shows little
> activity and the 15 HP electric motor is tiny compared to the 240 HP gas
> motor.

thats kinda cool. i wonder if they can use that in place of balance shafts?

 

In article <hF21e.96152$vK5.62707@twister.nyroc.rr.com>,
dm@nospam.com (Dave) wrote:

> In article <d22387$b83$1@blue.rahul.net>, dold@XReXXItXsX.usenet.us.com wrote:
>
> >I wonder what kind of mileage the civic would get if
> >it just had the 1300cc engine, and no IMA. It is very simple to
> >understand, and rather obvious in operation.
>
> Honda did report on this. I forget the exact numbers, but it is
> something like 1/3 due to the hybrid itself (regen, more efficient
> power management), 1/3 engine downsizing and advanced technology,
> and 1/3 lightweighting of the vehicle. Something like that.

But the Accord Hybrid is rather different. As far as I can tell, the
electric motor is to keep the engine running smoothly when it's
switching in and out of gas saving modes. The power meter shows little
activity and the 15 HP electric motor is tiny compared to the 240 HP gas
motor.


> >I don't understand the Escape very well yet.
>
> Same as Prius. See other posts.
>
> >I picture today's Escape as a Gas-Electric Hybrid, where the next
> >generation might be an Electric-Gas Hybrid.
>
> Definitely doable. But it all depends what you want out of a
> vehicle, and what you are willing to pay. Extended operation off
> the battery requires a bigger, higher energy capacity battery.
> The cost of the battery (and mass and volume) are pretty much
> directly proportional to that energy capacity.
>
> And if you want sustained performance, ex: climbing Baker Grade in
> california towing a trailer, you still need a lot of continuous
> capability.

 

"TE Cheah" <no@spam.biz> wrote in message news:424652dd_2@news.tm.net.my...
> Using a pronoun @ the start of a paragraph / sentence, before
> the subject matter is introduced, indicates low IQ ; nobody will
> know what the pronoun represents, before the subject matter is
> introduced.
>
>
What are you talking about???

Mike

 

<dold@XReXXItXsX.usenet.us.com> wrote in message
news:d23ugc$geh$5@blue.rahul.net...
> In rec.autos.makers.honda Michael Pardee <michaeltnull@cybertrails.com>
> wrote:
>> However, the full electric torque is available. The torque is
>> considerable -
>> 295 ft-lb compared with the rated 82 ft-lb from the engine - so the
>> stories
>> of getting stuck in potholes are urban legend. (But note the torques
>> aren't
>> directly comparable because of the effect of the power split device...
>> the
>> electric provides something like 2/3 of the torque at the wheels.) At any
>> rate, I can attest from our 40K miles experience with a 2002 model it
>> just
>> isn't a problem.
>
> I have an Escape, so the "2002 model" caught me off guard there. The
> getting stuck part is being written as first hand in the Edmunds forum.
> <http://townhall-talk.edmunds.com/WebX?ed_searchResults@89.SvGQc8EKYPT.1@.ef0f4df!ke ywords=allin%3Amsgtext%20limit%3A.ef0f4df%20stuck& count=20>
>
> It is said that applying throttle slowly doesn't work, because of overload
> sensing. I have gotten "stuck" in a small ditch on my property. I seemed
> stuck, but I had read the posting, so I got "more aggressive" with the
> throttle. I might go try it again, with a normally cautious application
> of
> power, and see if the motor gives up.
>
>> The engine is a resource of the hybrid computer and is only
>> under the most indirect control of the driver... about the way your heart
>> rate is under your control. I can floor the accelerator with the shifter
>> in
>> "park" and hold it there. The engine gradually revs, reaching a peak of
>> 2250
>> rpm in a couple of minutes. Imagine trying to shift that arrangement.
>
> I had toyed with the lack of response, but hadn't held it there...
>
Ah - there is an "issue" with the way it handles wheel slippage. In the
older Toyota Hybrid System (THS), like in our 2002 Prius, the hybrid
computer handles wheel spin in an unsophisticated version of traction
control. In snow for example, we just push the throttle down somewhat and
the system does a sort of slow ABS in reverse, cutting power for perhaps 1/2
second when it detects wheel spin. It works well for slippery starts and
slippery hills. Apparently the Synergy Hybrid System (SHS) Toyota has made
since 2004 MY (and licensed to Ford for the Escape) responds by shutting
down power completely at ordinary throttle settings, leaving the driver
sitting until the throttle is either released or floored. I'm told the
behavior at full throttle is what I'm used to at any throttle setting. I
don't think I'd like the new way, and I don't know why Toyota changed the
hybrid computer program. I'd think having the accelerator floored when
finally getting to good road surface could be unsettling.

What surprises me is that the hybrid computer could be programmed for the
most intelligent way of handling wheel spin. The computer tightly controls
the MG2 speed; why isn't it programmed to calculate the friction it
encounters and adjust to the best torque for the conditions? It could even
be programmed to rock safely out of a hole, something that is forbidden to
the driver in the Prius (and many modern cars - my daughter's '93 Accord
expressly forbids it too.) It would require a special "gear" (selection on
the shifter - there are no gears anyway) and some lines of code but it would
be a boon. It could be far more effective than even the most experienced
driver, because it could control torque instantaneously and map the friction
contour of the hole as it worked. Maybe someday....

Mike

 

In rec.autos.makers.honda Michael Pardee <michaeltnull@cybertrails.com> wrote:
> However, the full electric torque is available. The torque is considerable -
> 295 ft-lb compared with the rated 82 ft-lb from the engine - so the stories
> of getting stuck in potholes are urban legend. (But note the torques aren't
> directly comparable because of the effect of the power split device... the
> electric provides something like 2/3 of the torque at the wheels.) At any
> rate, I can attest from our 40K miles experience with a 2002 model it just
> isn't a problem.

I have an Escape, so the "2002 model" caught me off guard there. The
getting stuck part is being written as first hand in the Edmunds forum.
<http://townhall-talk.edmunds.com/WebX?ed_searchResults@89.SvGQc8EKYPT.1@.ef0f4df!ke ywords=allin%3Amsgtext%20limit%3A.ef0f4df%20stuck& count=20>

It is said that applying throttle slowly doesn't work, because of overload
sensing. I have gotten "stuck" in a small ditch on my property. I seemed
stuck, but I had read the posting, so I got "more aggressive" with the
throttle. I might go try it again, with a normally cautious application of
power, and see if the motor gives up.

> The engine is a resource of the hybrid computer and is only
> under the most indirect control of the driver... about the way your heart
> rate is under your control. I can floor the accelerator with the shifter in
> "park" and hold it there. The engine gradually revs, reaching a peak of 2250
> rpm in a couple of minutes. Imagine trying to shift that arrangement.

I had toyed with the lack of response, but hadn't held it there...

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

 

In rec.autos.makers.honda Dave <dm@nospam.com> wrote:
> In article <d22387$b83$1@blue.rahul.net>, dold@XReXXItXsX.usenet.us.com wrote:

>>I picture today's Escape as a Gas-Electric Hybrid, where the next
>>generation might be an Electric-Gas Hybrid.

> Definitely doable. But it all depends what you want out of a
> vehicle, and what you are willing to pay. Extended operation off
> the battery requires a bigger, higher energy capacity battery.

I would have purchased a pure electric car, except that it didn't have
enough range. If the Electric-Gas hybrid had an electric-only range of
30-40 miles, that would suffice for most around town runs, but the gas
would always be available for the cross country jaunts.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

 

In article <1j0a4111jued6b7v3vic0279rfq110tuc5@4ax.com>, gRmEcMgOrVeEw@mindspring.com (Gordon McGrew) wrote:
>On Fri, 25 Mar 2005 12:00:04 GMT, dm@nospam.com (Dave) wrote:

>>I wonder how many folk who buy the tiptronic type actually
>>manually shift. [...]

>Probably a good thing too as you would probably wear it out if you
>started aggressively shifting it. The Problem is that Tiptronic et
>al. don't really give you the control of an MT in that you can't
>separate the engine from the drive train to allow rpm matching.

Ah, but it is a fluidic separation between the two through the
torque converter. So, what are you saying would wear out?

 

On Fri, 25 Mar 2005 12:00:04 GMT, dm@nospam.com (Dave) wrote:

>In article <4243de3a_4@x-privat.org>, "dragon" <dondragon38@hotmail.com> wrote:
>>> >
>>> Well, now the trend is to have both manual and auto trannies on the same
>>car
>>> which is called million different names such as autostick, tiptronic,
>>> easytronic, multimod manual, activeselect or whatever...
>>
>>of course, i didn't mean that these cars have 2 transmissions...just one
>>with with the capabilities of both both manual and auto transmission...
>
>Yes, I wonder how they (NHTSA) are defining "manual". Some of the
>ones you listed are typical torque converter ("slushboxes") where
>they just add a manual shifting mode. Others have actual manual
>trannies, just with an electronic clutch, ex: BMW's SMG. I
>believe your "Easytronic" is the latter?

I would be surprised if these were classified as MTs. The stats
actually specify % AT and I would bet that any transmission that had
the capability to fully automatic would qualify. You have always been
able to manually shift an AT if you like.

>I wonder how many folk who buy the tiptronic type actually
>manually shift. When I've driven those, I get tired of the
>novelty in the first drive and just end out driving them like
>every other automatic.

Probably a good thing too as you would probably wear it out if you
started aggressively shifting it. The Problem is that Tiptronic et
al. don't really give you the control of an MT in that you can't
separate the engine from the drive train to allow rpm matching. Now
if they would use the same system used in the F1 cars it might be a
different story. But I think even they have a clutch pedal for
standing starts.

 

In rec.autos.makers.honda Michael Pardee <michaeltnull@cybertrails.com> wrote:
> Reverse is MG2 all the way.

I had heard that. But at stall, that's 94 HP, isn't it? I've heard of
people getting stuck in potholes, because they couldn't move forward and
didn't have the power to move backward. I was trying to decide how I could
test for that.

> At full output, a significant part of the engine power is channeled through
> MG1 to MG2. That part limits the power of the system because the power can
> only be counted once. For example, if you have a 100 hp engine and a 50 hp
> motor, but at full power 20 hp of the motor output comes from the engine
> through MG1 (rather than from the battery) the total is only 130 hp.

I've heard that this power arrangement, where MG1 is draining power during
highest power demand, is due in part to the battery not having enough of an
amperage rating to drive MG2 at full power, but I wonder about that. Maybe
it just isn't efficeient to run at full power from the batteries for very
long, due to the total amp-hours available, and a balance has been
found that is more efficient.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

 

<dold@XReXXItXsX.usenet.us.com> wrote in message
news:d22nvu$s39$3@blue.rahul.net...
> In rec.autos.makers.honda Dave <dm@nospam.com> wrote:
>> http://www.me.utexas.edu/~tomr/body.htm
>
> That has a drawing of a "conventional" (Honda-like) CVT that made me think
> the article was all wrong. It's a paragraph or two later that it explains
> the Toyota PSD, but even then the picture is wrong. It looks like the MG1
> and CE are slaved on a single shaft.
>

Yep - forget about that site. It's pretty messed up. It also describes the
SHS as having two 67 hp motors, while MG1 is about half that capacity.

>> <http://home.earthlink.net/~graham1/MyToyotaPrius/Understanding/PowerSplitDevice.htm>
>
> That made interesting reading. Doesn't cover all of the operation, but I
> can fill in the rest... MG1 must be the "starter motor". MG2 supplies
> regen braking. But I think I understand it now... The oddities are
> compromises. It all makes sense.
>
Something like that. The engine is spun up by differential between MG1 and
MG2, and regen braking is almost exclusively MG2. Reverse is MG2 all the
way. When driving, MG1 is primarily responsible for controlling the engine
load (virtual gear ratio), and it is in that role it operates as a
generator.

> I don't see how it relates to the "combined HP" being less than additive
> between the MG2 and the ICE. The MG2 maximum would be related to road
> speed. The ICE could be held at its maximum HP, and the RPM of that has
> little to do with the RPM of MG2. The MG1 output would be lower as ICE
> went higher, so there would eventually be some electrical starvation as
> the
> batteries depleted, but it seems that you should be able to see maximum
> MG2
> horsepower added to the maximum ICE horsepower, at least for a few
> seconds,
> and maybe only at one particular road speed.
>
At full output, a significant part of the engine power is channeled through
MG1 to MG2. That part limits the power of the system because the power can
only be counted once. For example, if you have a 100 hp engine and a 50 hp
motor, but at full power 20 hp of the motor output comes from the engine
through MG1 (rather than from the battery) the total is only 130 hp.

Mike

 

Kevin McMurtrie wrote:

> In article <n1n6415e4ld5568b02dss1lue7vccg1us2@4ax.com>,
> gRmEcMgOrVeEw@mindspring.com (Gordon McGrew) wrote:
>
>
>>There are lots of great statistics at the Government CAFE web site.
>>Lots of compiled data on cars going back to 1977 (and some even
>>older.) One interesting trend tracked is the percentage of
>>automobiles with automatic transmissions.
>>
>>In 1977, 84.1% of all new cars had AT. Under pressure of demands for
>>improved fuel economy and increasing consumer preference for import
>>cars, that number dropped to 75.0% in 1987. Then imports went
>>upscale, ATs became more sophisticated and fuel got cheap. By 2002,
>>88.5% of new cars had only two pedals and the imminent demise of the
>>manual transmission was widely predicted.
>>
>>Then something funny happened. There were rumors of rebellion in the
>>ranks and increased reports of drivers demanding control of the gear
>>ratios. In 2003, the percentage of cars sold with automatics dropped
>>precipitously to 82.4%. The CAFE site is now reporting a further drop
>>in 2004 with the lowest percentage of AT's since 1991, 79.6%. That
>>means that the number of cars sold with manual transmissions increased
>>77% in only two years and a clutch is now found in one of every five
>>new cars.
>>
>>In terms of sales, this trend actually surpasses the much touted
>>return of rear wheel drive and the movement is broad based. While
>>keeping in mind that the politics of fuel economy can skew the
>>definitions pretty badly, the trend is apparent in domestics, Asian
>>and European imports. All are selling manual transmissions at levels
>>that haven't been seen in a decade. Almost half of all European cars
>>are now shifters, the highest rate since 1988.
>>
>>Will this be a long lasting trend or a brief flash? It is still too
>>early to tell but it certainly shows that the old MT is going to be
>>harder to kill than it once appeared. The auto companies have now
>>learned that there is a solid base of buyers who prefer to shift for
>>themselves and the increased availability of this option is sure to
>>follow.
>>
>>
>>http://www.nhtsa.dot.gov/cars/rules/...erCarFleet.htm
>
>
> On the other hand, you can't have hybrid gas/electric with MT. It's
> kind of a bummer because I like responsiveness of manuals but the
> milage*power level is falling behind some automatics. Regenerative
> braking, continuous gear ratios, ultra-lean burn, and cylinder bypassing
> need to be coordinated with an AT. The decision was much more clear-cut
> a few years ago when you chose between a peppy 5-speed manual or a
> sluggish 3-speed automatic. Now cars like the Accord Hybrid make the
> decision tough.

Say again? A quick look at the Yahoo Autos tells me that the 2005
Civic Hydrid is available with a 5-speed manual transmission. The
same goes for the Insight.

 

In rec.autos.makers.honda Dave <dm@nospam.com> wrote:
> http://www.me.utexas.edu/~tomr/body.htm

That has a drawing of a "conventional" (Honda-like) CVT that made me think
the article was all wrong. It's a paragraph or two later that it explains
the Toyota PSD, but even then the picture is wrong. It looks like the MG1
and CE are slaved on a single shaft.

> <http://home.earthlink.net/~graham1/MyToyotaPrius/Understanding/PowerSplitDevice.htm>

> I can't vouch for it being 100% correct, but it is similar to what

That made interesting reading. Doesn't cover all of the operation, but I
can fill in the rest... MG1 must be the "starter motor". MG2 supplies
regen braking. But I think I understand it now... The oddities are
compromises. It all makes sense.


The Honda Charge/Assist displays what I expect it to display. When I floor
the gas pedal, the assist goes full, and stays there. Because the IMA has
a power peak at 4000 RPM, I would really expect the bar graph to drop off
some above 4000 engine RPM, but maybe that's literary license for the
masses, who wouldn't want the graph to reduce while demand is full.


In the Escape, flooring it gives near full assist for a little bit, then
swings to charge. That confused me, but it is clearer now. That only
happens at higher speeds. (I actually went out and drove the Escape to
test my new thoughts.) It is because MG2 is tied to the wheels, and has a
peak power at some road speed. I might guess that it's 47mph, where the
EPA highway test runs ;-) It is above thirty, and less than sixty. At
about 10mph, going up a steep hill, flooring it leaves it at full assist,
like I would expect, for the duration of my little test run.

The Escape ICE seems to go to about 4,000 RPM under almost any enthusiastic
"gas pedal" position. The MG2 speed would change exactly as the road speed
changed, with good power up to a road speed that I could calculate if I
went back to Graham's page. The MG1 RPM would change inversely as the road
speed increased if the engine stayed at 4,000 RPM.

I don't see how it relates to the "combined HP" being less than additive
between the MG2 and the ICE. The MG2 maximum would be related to road
speed. The ICE could be held at its maximum HP, and the RPM of that has
little to do with the RPM of MG2. The MG1 output would be lower as ICE
went higher, so there would eventually be some electrical starvation as the
batteries depleted, but it seems that you should be able to see maximum MG2
horsepower added to the maximum ICE horsepower, at least for a few seconds,
and maybe only at one particular road speed.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

 

In rec.autos.makers.honda Dave <dm@nospam.com> wrote:
>>reference for how it really works? I've seen some misguided crud, but no
>>real explanation. I assume that it is the same as the Prius, so reference
>>to that would be good, unless I can spot a discrepancy.

> Try this treatise:
> http://home.earthlink.
> net/~graham1/MyToyotaPrius/Understanding/PowerSplitDevice.htm

> I can't vouch for it being 100% correct, but it is similar to what
> I've read before about the Toyota hybrid drive. Basically, by
> varying the motor/generator1 speed, one can control the ICE rpm.

> It's pretty neat, but also complex. 2 high-power
> motor/generators.

> Another reference:
> http://www.me.utexas.edu/~tomr/body.htm


--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

 

"Dave" <dm@nospam.com> wrote in message
news:hF21e.96152$vK5.62707@twister.nyroc.rr.com...
> And if you want sustained performance, ex: climbing Baker Grade in
> california towing a trailer, you still need a lot of continuous
> capability.

Definitely. This will probably be an area where hybridization appears last -
towing packages and trucks of all sorts. The IMA approach is still
attractive (in a technical sense) in that it can improve passing ability and
the ability to gain speed after a stop, but I think it will be a long time
before the economics of that make sense. Turbocharging is better for towing
and trucks, and even that still isn't universal yet.

And as to the topic, I've driven manual and AT rental trucks up grades and I
despise autos for that sort of thing. They also bite the big one off road,
especially on slippery snow/mud roads. Throttle/slippage is much easier to
control with a manual.

Mike

 

"Dave" <dm@nospam.com> wrote in message
news:1A21e.96151$vK5.73947@twister.nyroc.rr.com...
> In article <5_udnd1bQuf3E9nfRVn-3g@sedona.net>, "Michael Pardee"
> <michaeltnull@cybertrails.com> wrote:
>
>>That site is by Graham Davies, one of the genuine Prius gurus. He writes
>>that he looked into it very carefully, and it is true - under many
>>conditions MG1 is used as a generator to provide power to MG2. It makes my
>>head hurt to visualize it.
>
> Yep. That's how you can have a 50 kW motor, but only a 25 (30?)
> kW battery driving it. Sometimes, actually quite often, at least
> part of the electric power to drive the second motor comes from
> the ICE driving the first motor as a generator. Basically, an
> electric transmission. Generally I would not expect that
> to be as efficient as a mechanical clutch.
>
> So the Prius system acts as both a mechanical and electrical
> transmission.

The efficiency is supposed to be about 90%, considerably less than a manual
gearbox. OTOH, it allows the engine to operate in more efficient ranges more
of the time, so it's an overall gain in city driving. On the freeway it
would be hard to beat a manual tranny for efficiency. (I understand ATs with
lockup come close.)

There is a narrow speed/power mode where MG1 is stationary and the
transmission is strictly mechanical. I think that speed is different in the
first generation Prius (before 2004 MY) than with the second generation,
because the MG maximum speeds are different now.

Mike