>> To me a proper hybrid should have the IC engine sized for the AVERAGE
>> hp required by the vehicle, NOT the peak.

If you were to do that, such a vehicle could never cross the Rocky
mountains. The IC engine has to be able to carry well above the average
load- say something that could maintain 50 mph up a 10% grade at max GVW
without any electric assist.

Steve wrote:
>
> >> To me a proper hybrid should have the IC engine sized for the AVERAGE
> >> hp required by the vehicle, NOT the peak.
>
> If you were to do that, such a vehicle could never cross the Rocky
> mountains. The IC engine has to be able to carry well above the average
> load- say something that could maintain 50 mph up a 10% grade at max GVW
> without any electric assist.

No, it's perfectly reasonable to largely drain the battery pack on the
up side and collect some energy back from regenerative braking on the
down side.

Driving consists of a pattern of very high power requirements and very
low power requirements and only if the usage pattern is reasonably
constant is it possible to tune a truly efficient hybrid system.

Ideally the IC engine is sized to that it can provide the average power
required by the vehicle. When more power is required it is provided by
the batteries and when less is required the batteries can be charged.
What you have is really a fully electric vehicle with onboard generator.
This setup is really quite a bit different than the hybrids they are
producing today. I saw a program recently that showed a modified
diesel-electric train engine that was similar.

For those who are not aware, a "diesel train" is really a
diesel-electric train and the diesel engine has no mechanical connection
to the wheels. The diesel engine drives a generator to produce
electricity and the electricity is then used to power the electric
traction motors. In this conventional setup there is no energy storage
and the diesel genset has to be sized to provide 100% of the peak power
requirements. For a cross country train with a very variable load
condition this isn't that inefficient.

For a diesel-electric train engine that is used exclusively in a rail
yard to move cars around the conventional setup is quite inefficient. In
this application the engine spends a large percentage of it's time
sitting idle with the diesel engine running. It's not practical to start
and stop these large engines like you would a car for a number of
reasons. Because of this there is a lot of potential energy wasted while
the engine is idling.

The new "hybrid" yard engine I saw on the program had been redesigned
with a much smaller diesel genset and a large bank of batteries. The
smaller genset is not large enough to provide full power, only the
average power and the batteries provide the additional power needed for
operation. The diesel engine is still left running all the time, but
during the time the yard engine is not in use the power generated is
charging the batteries, replacing the power used during operation. The
end result is significantly less fuel consumption and pollution.

With current battery technology this is only feasible in very
predictable applications such as the yard engine. The current crop of
"hybrid" cars do not even get close to this level of efficiency since
they really do little more than "peak shaving" and some regenerative
braking. To approach this efficiency the cars would need significantly
larger battery packs and probably a small turbine genset that would run
continuously.

I don't think the public is ready for a car that runs all the time,
certainly garages aren't made to have a running vehicle in them. Battery
technology would also need to improve to keep a pack of the needed
capacity from exceeding practical size and weight limits.

As it stands right now, the available hybrids are only for those trying
to make a statement. Even with tax incentives and heavy discounting by
the manufacturers you would be hard pressed to make up the cost
difference in gas savings. When you factor in the service life of the
battery pack you are *absolutely* loosing money over buying a
conventional car. Even if you ignore the true economics of it, you are
still getting a less capable vehicle for your money vs. a conventional.

I've not personally tried a hybrid, but from what I've heard from
friends that have, they are rather under powered for anything past two
adults and a bag of groceries. That may be adequate for 15% of the
population, but 15% does not drive the market.

I've got nothing against hybrids, but until I can get a hybrid that is
capable of pulling my 10,000# trailer, or carrying 4,000# of cargo
directly it simply isn't feasible for me. I don't need to tow or carry
such loads daily, but with current tax and insurance policies it is not
economically feasible to have a second smaller vehicle for general use.

A simple way to reduce oil consumption that requires no new technology
at all is to adjust the laws so that you do not pay extra taxes or
insurance on a second vehicle (hybrid or conventional) that meets some
reasonable mileage threshold such as 35 mpg. A lot of people who need
larger pickups/vans/suvs for a variety of reasons would then be able to
justify a smaller car for their general use.

A key factor here is that you are providing incentives to operate more
efficiently overall, not incentives to be a technology guinea pig. You
can buy a small used car (Civic, etc.) for far less than a new hybrid
which makes this option reasonable for people who do not have money to
burn and are not interested in making a statement.

As a good example think of a small contractor doing perhaps siding or
painting. They need to have a full sized pickup/van getting perhaps 18
mpg for their work. Siding and painting are not high pay trades so they
don't have the Mercedes or BMW to use after work. They have to take that
same pickup or van out to get groceries or to go see a movie or perhaps
to see their kids baseball game. If they were able to get a smaller
vehicle for after work use without paying a heavy tax and insurance
penalty they likely would. They would save on gas, have easier parking
and reduce the risk of having tools stolen from their truck.

Pete C.

Pete C. wrote:

>
> Steve wrote:
>
>>>>To me a proper hybrid should have the IC engine sized for the AVERAGE
>>>>hp required by the vehicle, NOT the peak.
>>
>>If you were to do that, such a vehicle could never cross the Rocky
>>mountains. The IC engine has to be able to carry well above the average
>>load- say something that could maintain 50 mph up a 10% grade at max GVW
>>without any electric assist.
>
>
> No, it's perfectly reasonable to largely drain the battery pack on the
> up side and collect some energy back from regenerative braking on the
> down side.

The designer can't know going in how long a driver might need to run in
a mode that is draining the battery. What is the longest climb in North
America? Is that the limit? What if the vehicle is pulling a trailer
over that same climb? Is that the limit? Or do you just size the IC
engine so that it can maintain a "reasonable" speed even with the
battery depleted and at max GVW. Seems like the latter is what all the
hybrid designs thus far actually do. The ones that have a higher GVW
(like SUVs that are rated to tow trailers) get a bigger IC engine. You
still get a huge net benefit from a hybrid driveline, even with a bigger
"reserve power" in the IC engine.

In message >, Steve >
writes
>The designer can't know going in how long a driver might need to run in
>a mode that is draining the battery. What is the longest climb in North
>America? Is that the limit? What if the vehicle is pulling a trailer
>over that same climb? Is that the limit? Or do you just size the IC
>engine so that it can maintain a "reasonable" speed even with the
>battery depleted and at max GVW. Seems like the latter is what all the
>hybrid designs thus far actually do. The ones that have a higher GVW
>(like SUVs that are rated to tow trailers) get a bigger IC engine. You
>still get a huge net benefit from a hybrid driveline, even with a
>bigger "reserve power" in the IC engine.
The trade-off is reduced co2 emissions when compared to a pure IC engine
providing the same acceleration.
The downside is increased complexity and therefore increased up-front
capital cost.
Hybrids can provide big car feel (extra mass of battery etc.) with small
car economy.
A country serious about emissions would offset the increased capital
cost against the reduced fuel consumption (virtual fuel?) neither Europe
or the US has done this.
I drive a turbo diesel with poor low speed acceleration but good
economy I would expect an equivalent hybrid to cost more, have similar
or better economy but have good low speed acceleration, note that the
design compromises necessary to provide good torque over the entire rev
range limits the IC power to weight/efficiency so the reduced rev range
of the hybrid can give good hill climbing at its optimum (reduced) rev
range.

I observe that except in special circumstances all consumer items ( and
species) get more complex as they evolve hybrids this is the way to go
for reduced emissions not hydrogen fuel which seems to simply move the
point of emission somewhere else.

Auntie spam measure use

--
dd

Steve wrote:
>
> Pete C. wrote:
>
> >
> > Steve wrote:
> >
> >>>>To me a proper hybrid should have the IC engine sized for the AVERAGE
> >>>>hp required by the vehicle, NOT the peak.
> >>
> >>If you were to do that, such a vehicle could never cross the Rocky
> >>mountains. The IC engine has to be able to carry well above the average
> >>load- say something that could maintain 50 mph up a 10% grade at max GVW
> >>without any electric assist.
> >
> >
> > No, it's perfectly reasonable to largely drain the battery pack on the
> > up side and collect some energy back from regenerative braking on the
> > down side.
>
> The designer can't know going in how long a driver might need to run in
> a mode that is draining the battery. What is the longest climb in North
> America? Is that the limit? What if the vehicle is pulling a trailer
> over that same climb? Is that the limit? Or do you just size the IC
> engine so that it can maintain a "reasonable" speed even with the
> battery depleted and at max GVW. Seems like the latter is what all the
> hybrid designs thus far actually do. The ones that have a higher GVW
> (like SUVs that are rated to tow trailers) get a bigger IC engine. You
> still get a huge net benefit from a hybrid driveline, even with a bigger
> "reserve power" in the IC engine.

That's exactly why the technology isn't ready for general use yet.
Limited predictable applications first such as local deliveries (hello
USPS, UPS, FedEx, etc.), public transportation (you ought to know your
bus routes pretty well) Think school busses too, not just city busses
since more kids commute via buss than adults. This is where the current
technology can do the most good and also where it can mature to become
more practical for consumer use.

Let folks who want to make a statement ignore the true costs if they
want, but focus the efforts and any legislation on what is practical. In
my opinion what is practical now is hybrids in some commercial
applications and tax/insurance breaks for people to use a second higher
mileage vehicle for general use as I noted previously.

Pete C.

Joe S wrote:
>
> I don't understand what you're saying....are you saying that the hybrid
> model of whichever vehicle you are referring to (which is it, by the
> way?) consumes more gasoline than it's convential version?
>
> I know that the Escape hybrid gets much better mileage than it's
> conventional counterpart. So, again, some specifics?
>
>
> Joe
>
I don't have the numbers on the Escape- maybe you could provide them.

However, on the model I used as an example, it did get a little better
milage with the hybrid version, but not by a whole lot. If they made
the IC engine smaller and the electric larger, the improvement would be
a lot greater. Again, keep the TOTAL the same, so performance would be
the same (except for racing, when the average horsepower demand remains
high), with a better increase in milage.

Steve wrote:

>
>
>>> To me a proper hybrid should have the IC engine sized for the AVERAGE
>>> hp required by the vehicle, NOT the peak.
>
>
> If you were to do that, such a vehicle could never cross the Rocky
> mountains. The IC engine has to be able to carry well above the average
> load- say something that could maintain 50 mph up a 10% grade at max GVW
> without any electric assist.
>
>

Gee, I used to have a couple of cars that wouldn't maintain 50 up some
of those grades. But I made it over the mountains. I didn't drive over
them every year, though, and didn't take those trips every year.

I would say that someone who lives in Rocky Mountain states might indeed
not be a good customer for a hybrid. But there are MANY of us who
seldom cross the Rockies, and I'd be satisfied, in years that I do take
a trip out west, to go up the mountains at the speed of my old Chrysler
slant six, in order to get better milage for 99% of the drives I DO make.

Don Stauffer in Minneapolis wrote:
> Joe S wrote:
> >
> > I don't understand what you're saying....are you saying that the
hybrid
> > model of whichever vehicle you are referring to (which is it, by
the
> > way?) consumes more gasoline than it's convential version?
> >
> > I know that the Escape hybrid gets much better mileage than it's
> > conventional counterpart. So, again, some specifics?
> >
> >
> > Joe
> >
> I don't have the numbers on the Escape- maybe you could provide them.
>
> However, on the model I used as an example, it did get a little
better
> milage with the hybrid version, but not by a whole lot. If they made

> the IC engine smaller and the electric larger, the improvement would
be
> a lot greater. Again, keep the TOTAL the same, so performance would
be
> the same (except for racing, when the average horsepower demand
remains
> high), with a better increase in milage.


http://www.fueleconomy.gov/feg/findacar.htm

2005 Escape 2WD HEV - 36 City 31 Highway 33 Combined
2005 Escape 2WD (Conv 4-cyl IC Auto) - 22 City 25 Hwy

So, that's 60% improvement around town, 30% improvement on the highway
over its 4-cylinder brother.

So, please tell us what models you looked at?


Joe

Don Stauffer in Minneapolis wrote:
> Steve wrote:
> >
> > > > To me a proper hybrid should have the IC engine sized for the
> > > > AVERAGE hp required by the vehicle, NOT the peak.
> >
> > If you were to do that, such a vehicle could never cross the Rocky
> > mountains. The IC engine has to be able to carry well above the
> > average load - say something that could maintain 50 mph up a 10%
> > grade at max GVW without any electric assist.

> I would say that someone who lives in Rocky Mountain states might
> indeed not be a good customer for a hybrid.

The relevant considerations are certainly somewhat different in such
places from those applicable to driving in flattish areas.

ISTM that the IC engine of a hybrid should be sufficiently powerful
to be *able to do the job* without electrical assistance. If it is
not then you could find yourself in something of a pickle.

For most vehicles, for the vast majority of the time there will be
quite enough energy stored in the battery for a decent start from
the lights, to take a steep but shortish hill at a respectable pace,
or whatever.

A general-purpose hybrid (such as a car sold to the public, rather
than a bus sold to a city's transport company) should be *able* to
cross the Rockies on the IC engine alone (but not necessarily at
50 mph), otherwise the poor sap may have to stop simply in order to
run the IC engine to charge the battery to allow him to do the next
few miles on the IC engine plus electrical assistance, then stop
again to recharge the battery ...

Don Stauffer in Minneapolis wrote:
>
> Gee, I used to have a couple of cars that wouldn't maintain 50 up
some
> of those grades. But I made it over the mountains. I didn't drive
over
> them every year, though, and didn't take those trips every year.
>
> I would say that someone who lives in Rocky Mountain states might
indeed
> not be a good customer for a hybrid. But there are MANY of us who
> seldom cross the Rockies, and I'd be satisfied, in years that I do
take
> a trip out west, to go up the mountains at the speed of my old
Chrysler
> slant six, in order to get better milage for 99% of the drives I DO
make.

I've had cars that probably wouldn't have gotten over the Rockies;
luckily I never needed to. We've always been a two-car family. One
car is sized for local-only use with only minor hills. The other is
more appropriate for longer highway trips that might take us a few
thousand miles in comfort -- maybe even over the Rockies -- on a week's
vacation. We'd be good customers for a high-MPG hybrid with a small IC
engine for daily, local use, and I bet there are plenty like us.