Rather than it get lost in the pointless drivel (dribble?) in the Petrol v
Diesel (Prius) squabble I'll start this new thread.

One of the many programs I've written over the years to help me in my
automotive related business is a spreadsheet which calculates the power and
fuel useage a car requires to travel at a given speed. It takes the weight,
rolling resistance, frontal area and drag coefficient, works out the wheel
bhp and flywheel bhp required at each speed from these and then applies
average BSFC (brake specific fuel consumption) data for both petrol and
diesel engines to calculate the fuel requirement and mpg. You can also enter
the price per litre of each fuel and it will calculate the pence per mile
fuel use.

You can also alter the speed in any of the calculation rows to a new value
and it'll tell you how much power you'll need to achieve that top speed and
what the fuel consumption would then be.

By playing with the car weight and drag data you can find out very quickly
what factors affect power requirement and fuel consumption. Basically weight
affects rolling resistance which is a big factor at low speed but not at
high speed and aerodynamic drag is the reverse. For good economy at low
speed you want a low weight vehicle and at high speed a low drag one.

Using it you can easily see what is needed to design a genuine 100 mpg car.
Low weight, low drag, efficient diesel engine. A 2000 lb car with low
rolling resistance tyres, 17 sq ft frontal area, 0.26 Cd drag (same as a
Prius) should do 110 mpg at 60 mph and 90 mpg at 70 mph with an efficient
diesel engine. For a one or two occupant vehicle this is not a difficult
concept to realise. The average hatchback in the 80s weighed less than that
and many cars such as the Mini have been much lighter.

This morning I've tweaked the program to be more user friendly and added
some guidelines for the data inputs for various cars. It's hosted here.

http://www.mediafire.com/?zk0mkoj41jx

It's an old Dos Borland Quattro format which is what I've used for donkey's
years for spreadsheet work cos I'm too set in my ways to use newfangled
windows spreadsheets but they should be able to recognise it without any
problem.

Play with the numbers and you'll see what your actual car ought to be giving
in mpg terms. If I enter the data for my Focus (3000 lbs, 0.013 RR, 22 sq
ft, 0.33 Cd) I get 38 mpg at 70 mph which is what it actually does. You can
then alter those numbers to see how easily we could all be driving small,
single user 100 mpg cars if the will were there or if fuel prices went up
enough.

We don't need hybrids, regenerative braking or any other unusual tactic (not
that I'm decrying them) to achieve this. Just common sense, efficient diesel
engines, low weight, size and drag.

In no more than 5 minutes I could sketch out a small streamlined car that
could carry two people and luggage and get them from London to Aberdeen on 5
gallons of fuel for 25 quid. My Focus needs three times that. If you want to
move house it won't be the ideal vehicle for you but as most cars only have
one person in them for 99% of the time it would do for most of us for
general use and commuting.
--
Dave Baker

On Wed, 28 Jan 2009 12:47:52 -0000, Dave Baker wrote:

Rather than it get lost in the pointless drivel (dribble?) in the Petrol v
Diesel (Prius) squabble I'll start this new thread.

One of the many programs I've written over the years to help me in my
automotive related business is a spreadsheet which calculates the power and
fuel useage a car requires to travel at a given speed. It takes the weight,
rolling resistance, frontal area and drag coefficient, works out the wheel
bhp and flywheel bhp required at each speed from these and then applies
average BSFC (brake specific fuel consumption) data for both petrol and
diesel engines to calculate the fuel requirement and mpg. You can also enter
the price per litre of each fuel and it will calculate the pence per mile
fuel use.

You can also alter the speed in any of the calculation rows to a new value
and it'll tell you how much power you'll need to achieve that top speed and
what the fuel consumption would then be.

By playing with the car weight and drag data you can find out very quickly
what factors affect power requirement and fuel consumption. Basically weight
affects rolling resistance which is a big factor at low speed but not at
high speed and aerodynamic drag is the reverse. For good economy at low
speed you want a low weight vehicle and at high speed a low drag one.

Using it you can easily see what is needed to design a genuine 100 mpg car.
Low weight, low drag, efficient diesel engine. A 2000 lb car with low
rolling resistance tyres, 17 sq ft frontal area, 0.26 Cd drag (same as a
Prius) should do 110 mpg at 60 mph and 90 mpg at 70 mph with an efficient
diesel engine. For a one or two occupant vehicle this is not a difficult
concept to realise. The average hatchback in the 80s weighed less than that
and many cars such as the Mini have been much lighter.

This morning I've tweaked the program to be more user friendly and added
some guidelines for the data inputs for various cars. It's hosted here.

http://www.mediafire.com/?zk0mkoj41jx

It's an old Dos Borland Quattro format which is what I've used for donkey's
years for spreadsheet work cos I'm too set in my ways to use newfangled
windows spreadsheets but they should be able to recognise it without any
problem.

Play with the numbers and you'll see what your actual car ought to be giving
in mpg terms. If I enter the data for my Focus (3000 lbs, 0.013 RR, 22 sq
ft, 0.33 Cd) I get 38 mpg at 70 mph which is what it actually does. You can
then alter those numbers to see how easily we could all be driving small,
single user 100 mpg cars if the will were there or if fuel prices went up
enough.

We don't need hybrids, regenerative braking or any other unusual tactic (not
that I'm decrying them) to achieve this. Just common sense, efficient diesel
engines, low weight, size and drag.

In no more than 5 minutes I could sketch out a small streamlined car that
could carry two people and luggage and get them from London to Aberdeen on 5
gallons of fuel for 25 quid. My Focus needs three times that. If you want to
move house it won't be the ideal vehicle for you but as most cars only have
one person in them for 99% of the time it would do for most of us for
general use and commuting.

The trouble is that although I may only need to move myself for commuting,
I need to transport myself, the wife and kids at other times, trolley(s),
diy bits and pieces, shopping, bulky items, etc., so I'd end up having to
own two cars. Most people - even singles - sometimes carry a carful and so
cars generally need to be big enough for the reasonably common occurences.

SteveW

Steve Walker wrote:
On Wed, 28 Jan 2009 12:47:52 -0000, Dave Baker wrote:

Rather than it get lost in the pointless drivel (dribble?) in the Petrol v
Diesel (Prius) squabble I'll start this new thread.

One of the many programs I've written over the years to help me in my
automotive related business is a spreadsheet which calculates the power and
fuel useage a car requires to travel at a given speed. It takes the weight,
rolling resistance, frontal area and drag coefficient, works out the wheel
bhp and flywheel bhp required at each speed from these and then applies
average BSFC (brake specific fuel consumption) data for both petrol and
diesel engines to calculate the fuel requirement and mpg. You can also enter
the price per litre of each fuel and it will calculate the pence per mile
fuel use.

You can also alter the speed in any of the calculation rows to a new value
and it'll tell you how much power you'll need to achieve that top speed and
what the fuel consumption would then be.

By playing with the car weight and drag data you can find out very quickly
what factors affect power requirement and fuel consumption. Basically weight
affects rolling resistance which is a big factor at low speed but not at
high speed and aerodynamic drag is the reverse. For good economy at low
speed you want a low weight vehicle and at high speed a low drag one.

Using it you can easily see what is needed to design a genuine 100 mpg car.
Low weight, low drag, efficient diesel engine. A 2000 lb car with low
rolling resistance tyres, 17 sq ft frontal area, 0.26 Cd drag (same as a
Prius) should do 110 mpg at 60 mph and 90 mpg at 70 mph with an efficient
diesel engine. For a one or two occupant vehicle this is not a difficult
concept to realise. The average hatchback in the 80s weighed less than that
and many cars such as the Mini have been much lighter.

This morning I've tweaked the program to be more user friendly and added
some guidelines for the data inputs for various cars. It's hosted here.

http://www.mediafire.com/?zk0mkoj41jx

It's an old Dos Borland Quattro format which is what I've used for donkey's
years for spreadsheet work cos I'm too set in my ways to use newfangled
windows spreadsheets but they should be able to recognise it without any
problem.

Play with the numbers and you'll see what your actual car ought to be giving
in mpg terms. If I enter the data for my Focus (3000 lbs, 0.013 RR, 22 sq
ft, 0.33 Cd) I get 38 mpg at 70 mph which is what it actually does. You can
then alter those numbers to see how easily we could all be driving small,
single user 100 mpg cars if the will were there or if fuel prices went up
enough.

We don't need hybrids, regenerative braking or any other unusual tactic (not
that I'm decrying them) to achieve this. Just common sense, efficient diesel
engines, low weight, size and drag.

In no more than 5 minutes I could sketch out a small streamlined car that
could carry two people and luggage and get them from London to Aberdeen on 5
gallons of fuel for 25 quid. My Focus needs three times that. If you want to
move house it won't be the ideal vehicle for you but as most cars only have
one person in them for 99% of the time it would do for most of us for
general use and commuting.

The trouble is that although I may only need to move myself for commuting,
I need to transport myself, the wife and kids at other times, trolley(s),
diy bits and pieces, shopping, bulky items, etc., so I'd end up having to
own two cars. Most people - even singles - sometimes carry a carful and so
cars generally need to be big enough for the reasonably common occurences.

SteveW


The microcar concept was done to death in britain, they were popular
for many decades, but no more. The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety. This could be solved
by using them on separate roadways, protected by steel barriers from
the big cars/trucks. Fuel efficiency is just one of several advantages
- purchase cost, road congestion gone, far fewer pedestrian
fatalities, parking space problems solved, etc. And greater safety and
much lower cost means more people could afford them, leading to more
job and business opportunities etc. They're a win win win win win
option as long as theyre kept away from the big cars.

Re Cd, no sane person would drive a microcar at high speed. But 40mph
max is more than enough to go round towns & cities.


NT

gurgled happily, sounding much like they were saying:

The microcar concept was done to death in britain, they were popular for
many decades, but no more. The passenger question isnt really an issue,
one can build cars for any number of people far smaller than what we
have on the road today.

The biggest issue that kills microcars is safety.

Not at all. You seem to be completely forgetting about things like the
Smart and various superminis.

"Dave Baker" wrote in message
...

Rather than it get lost in the pointless drivel (dribble?) in the Petrol v
Diesel (Prius) squabble I'll start this new thread.

It is pointless I agree, as the Prius is clearly the future and the best by
far. Swishhhhhhhhhhhhhhhhhhh

We don't need hybrids, regenerative braking or any other unusual tactic
(not that I'm decrying them) to achieve this.

Thank God you don't design cars!!!

"Dave Baker" wrote in message
...
Rather than it get lost in the pointless drivel (dribble?) in the Petrol v
Diesel (Prius) squabble I'll start this new thread.
SNIP

http://www.gordonmurraydesign.com/LN_T25.html

http://www.carmagazine.co.uk/Green-C...irst-pictures/

Not a Diesel. And I think he knows what he is talking about.

Baz

On 28 Jan, 14:55, Steve Walker wrote:
On Wed, 28 Jan 2009 12:47:52 -0000, Dave Baker wrote:
Rather than it get lost in the pointless drivel (dribble?) in the Petrol v

We don't need hybrids, regenerative braking or any other unusual tactic (not
that I'm decrying them) to achieve this. Just common sense, efficient diesel
engines, low weight, size and drag.




SteveW- Hide quoted text -

- Show quoted text -

I agree we don't need Hybrids .. what we need is an escalation by
HMgov to roll out Hydrogen fuel refill points.
The Hydrogen fuelled car with no batteries is the single most
important invention for the automotive industry.
http://automobiles.honda.com/fcx-cla...fcx-works.aspx

Honda has it in production and the sooner it reaches UK the
better .... ZERO emissions .... fuel produced by simple electrolysis
of water - which can be easy & cheap, no expensive & heavy batteries
to run out.

If the tree huggers want to be really good, via wind wave or whatever.

I'd be happy with it coming form a Nuclear Plant.

In article , Adrian
scribeth thus
gurgled happily, sounding much like they were saying:

The microcar concept was done to death in britain, they were popular for
many decades, but no more. The passenger question isnt really an issue,
one can build cars for any number of people far smaller than what we
have on the road today.

The biggest issue that kills microcars is safety.

Not at all. You seem to be completely forgetting about things like the
Smart and various superminis.

Bu**ered if I'd have one nothing quite like a good Six feet of metal in
front of U
--
Tony Sayer

"Osprey" wrote in message
...

I agree we don't need Hybrids .. what we need is an escalation by
HMgov to roll out Hydrogen fuel refill points.
The Hydrogen fuelled car with no batteries is the single most
important invention for the automotive industry.
http://automobiles.honda.com/fcx-cla...fcx-works.aspx

The Honda is a hybrid. Where do we get the hydrogen? Where do we store the
stuff? The reliability of the fuel cell? OK that can be overcome in time.
The idea I like but it is the fuel that is the problem.

Honda has it in production and the sooner it reaches UK the
better .... ZERO emissions ....

Production? Where can we buy one?

fuel produced by simple electrolysis
of water - which can be easy & cheap, no
expensive & heavy batteries to run out.

It has a large battery set as it is electric drive. There is nothing so
simple as an all EV car. And when supercapacitors improve more, then they
will sing.

"Baz" wrote in message
...

"Dave Baker" wrote in message
...
Rather than it get lost in the pointless drivel (dribble?) in the Petrol
v Diesel (Prius) squabble I'll start this new thread.
SNIP

http://www.gordonmurraydesign.com/LN_T25.html

http://www.carmagazine.co.uk/Green-C...irst-pictures/

Not a Diesel. And I think he knows what he is talking about.

A 3-cylinder petrol engine. Nothing special there. What has to be
revolutionary is the propulsion unit, and this is not, just an old IC crock.
Although he says there is space for a fuel cell. Skoda could say that as
well. Looks like another Smart.

In article ,
Doctor Drivel wrote:

I agree we don't need Hybrids .. what we need is an escalation by
HMgov to roll out Hydrogen fuel refill points.
The Hydrogen fuelled car with no batteries is the single most
important invention for the automotive industry.
http://automobiles.honda.com/fcx-cla...fcx-works.aspx

The Honda is a hybrid.

Hybrid? Depends how you define that I guess - it certainly doesn't use any
petrol.

Where do we get the hydrogen?

Same argument for LPG - it'll become common I suspect

Where do we store the stuff?

Much like lpg... storage of hydrogen isn't a really a problem

The reliability of the fuel cell? OK that can be overcome in time.

Not sure that's a major issue... how reliable are batteries in a prius?

Honda has it in production and the sooner it reaches UK the
better .... ZERO emissions ....

Production? Where can we buy one?

Southern California IIRC

IMO, hybrids are a bodge - fuel cells seem radical enough change that they
might just be the answer...

Darren

"Doctor Drivel" wrote:


"Dave Baker" wrote in message
...

Rather than it get lost in the pointless drivel (dribble?) in the Petrol v
Diesel (Prius) squabble I'll start this new thread.

It is pointless I agree, as the Prius is clearly the future and the best by
far. Swishhhhhhhhhhhhhhhhhhh


I think you meant ...

Whoooossshhh!


Thank God you don't design cars!!!


Thank God none of our buying decisions will be based on your drivel.

(dmc) gurgled happily, sounding much like they were
saying:

I agree we don't need Hybrids .. what we need is an escalation by
HMgov to roll out Hydrogen fuel refill points. The Hydrogen fuelled
car with no batteries is the single most important invention for the
automotive industry.
http://automobiles.honda.com/fcx-cla...fcx-works.aspx

The Honda is a hybrid.

Hybrid? Depends how you define that I guess - it certainly doesn't use
any petrol.

Fine. So it's not a petrol-electric hybrid.

What it IS is a bit more difficult to classify - since the hydrogen's
being used as an electricity storage medium alone, it's probably fair to
refer to it as an electric-only vehicle.

Mind you, it's a thoroughly one when you look at the plug-to-motion
efficiency...

Where do we store the stuff?

Much like lpg... storage of hydrogen isn't a really a problem

splutter
It certainly is.

Look at BMW's 7-series hydrogen concept of a few years ago. The boot was
full of hydrogen tank, giving it a range of about 100 miles - which had
to be used within a week else it all escaped.

wrote in message
...
The microcar concept was done to death in britain, they were popular
for many decades, but no more. The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety.

The microcar concept is a million miles from what I'm contemplating here.
Making cars very small and very short is counterproductive in most respects.
Safety, luggage capacity and very importantly it makes it impossible to
generate a low drag shape.

It's nice to have low weight but it's not the major issue, or at least not
worth taking to extremes, especially if you have regenerative braking (RB).
The main issues are frontal area and Cd. So what we need are low, long,
narrow streamlined cars where's still plenty of metal between the passengers
and whatever they might hit at each end.

The Prius actually has many things close to right. It has a very low Cd by
virtue of length and careful streamlining. What it doesn't have right is
frontal area and weight although the RB counteracts much of the downside of
the latter. But, and it's a big but, if the car is heavy the performance is
crap unless the engine is large and that kills low speed consumption because
the engine isn't working efficiently and has high internal friction.

2000 lbs is not an extreme weight reduction measure. As I said it was a
perfectly normal weight before cars got bloated with safety features. With
modern materials that's plenty to build a decent sized car with but it must
have a lower frontal area than normal to get best consumption.

My target as I said was 2000 lbs, 17 sq ft and Cd of 0.26. That frontal area
only means the car being about 10% narrower and 10% lower than a Prius. Just
a few inches in each dimension. 21 x 0.9 x 0.9 = 17

Now you leave it comparitively long, say normal saloon car length, to
preserve luggage and passenger capacity and help with streamlining. It would
look a little unusual in its proportions but not unduly so. I can easily
conceive of a car weighing much less than 2000 lbs with modern materials but
it's not necessary to go that far.

Packaging could perhaps be a driver in the front with luggage space to his
left, two passengers behind him, maybe two child seats behind those as an
option and the boot space behind that with the spare seats easily removeable
to create a van/estate car. More innovative would be to have the drivetrain
to the left of the driver and more luggage space in the long streamlined
nose/crumple zone as well as in the rear.

Engine could be something like a 70 bhp diesel which would give adequate if
not sparkling performance due to the low weight. 0-60 mph in 12 seconds. A
90 bhp engine would drop that to 9 seconds which is starting to get
reasonably nippy.

This not a city car concept. It's an open road tourer capable of going long
distances with very low fuel consumption. Travel in cities is best dealt
with by other means - electric cars, small cars with RB and public
transport. Top speed would be about 110 mph, a five gallon tank would take
you from London to Aberdeen.
--
Dave Baker

In article ,
Adrian wrote:

Where do we store the stuff?

Much like lpg... storage of hydrogen isn't a really a problem

splutter
It certainly is.

Well, ok - maybe it's not *quite* that simple :-). It still seems to me the
most promising way of getting away from petrol/diesel in the near(ish)
future.

Someone just needs to work out a way of producing and distributing hydrogen
slush like they use on the shuttle :-)

Darren

"Dave Baker" wrote:

The microcar concept is a million miles from what I'm contemplating here.
Making cars very small and very short is counterproductive in most respects.
Safety, luggage capacity and very importantly it makes it impossible to
generate a low drag shape.


Low drag is completely irrelevant when driving at town speeds.

No-one is suggesting that a microcar is suitable for anything other than
low speed, short distance use.

(dmc) wrote:

Well, ok - maybe it's not *quite* that simple :-). It still seems to me the
most promising way of getting away from petrol/diesel in the near(ish)
future.

Someone just needs to work out a way of producing and distributing hydrogen
slush like they use on the shuttle :-)


Currently hydrogen is produced using electricity, over 80% of which is
generated by burning fossil fuels - therefore generating lots of CO2.

It is difficult to think of anything more pointless at this time than a
hydrogen fuel cell powered car. That will change when we have a lot
more power generated by nuclear and renewables. But that won't be for
at least another 15 years.

On Wed, 28 Jan 2009 16:45:40 +0000, Osprey wrote
(in article
):

Honda has it in production and the sooner it reaches UK the
better .... ZERO emissions .... fuel produced by simple electrolysis
of water - which can be easy & cheap

And where do you think the electricity to power your "simple electrolysis" is
produced? In power stations of course. And where is the energy coming from to
fuel your power stations? Yet more hydrogen?


The hydrogen fuel cell solves no energy problems.

--
Mike Lane
UK North Yorkshire

"dmc" wrote in message ...
In article ,
Doctor Drivel wrote:

I agree we don't need Hybrids .. what we need is an escalation by
HMgov to roll out Hydrogen fuel refill points.
The Hydrogen fuelled car with no batteries is the single most
important invention for the automotive industry.
http://automobiles.honda.com/fcx-cla...fcx-works.aspx

The Honda is a hybrid.

Hybrid? Depends how you define that I guess - it certainly doesn't use any
petrol.

Fuel = hydrogen
propulsion = electric motor
Energy storage = battery
Energy conversion = fuel cell

Hybrid it is.

Much like lpg... storage of hydrogen isn't a really a problem

It is highly volatile

The reliability of the fuel cell? OK that can be overcome in time.

Not sure that's a major issue... how reliable are batteries in a prius?

8 year guarantee expected average life = 12 yrs.
This Honda has a battery pack too.

Honda has it in production and the sooner it reaches UK the
better .... ZERO emissions ....

Production? Where can we buy one?

Southern California IIRC

Not that know of.

IMO, hybrids are a bodge - fuel cells seem radical enough change that they
might just be the answer...

The biggest bodge is attempting to make a an agricultural oil burning engine
perform like a petrol engine using all sorts of crap around it.

"Bruce" wrote in message
...

Thank God none of our buying decisions will be based on your drivel.

I am DR Drivel, I recognise drivel when I see it.

dmc wrote:
In article ,
Doctor Drivel wrote:

Where do we get the hydrogen?

Same argument for LPG - it'll become common I suspect


LPG comes out of the ground. Hydrogen has to be made - typically from
natural gas...

Andy

In article ,
Bruce wrote:

Currently hydrogen is produced using electricity, over 80% of which is
generated by burning fossil fuels - therefore generating lots of CO2.

Honda say:

"CO2 emissions related to the production of hydrogen vary by source;
however, well-to-wheel CO2 emissions using hydrogen reformed from natural
gas - the most widely used method of production today - are less than
half that of a conventional petrol vehicle. With the production of hydrogen
from water by electrolysis, CO2 emissions can be further reduced and
ultimately approach zero if the electricity is generated from sustainable
sources, such as solar, wind, hydro and wave power."

which sounds fantastic - but then it would from them wouldn't it

Interesting they don't mention nuclear as an option...

The 5,000-psi hydrogen storage tank is slightly scary as well - but then
everyone driving around with a plastic tank containing 10 gallons of
petrol is scary I guess..

It is difficult to think of anything more pointless at this time than a
hydrogen fuel cell powered car. That will change when we have a lot
more power generated by nuclear and renewables. But that won't be for
at least another 15 years.

I can't really see prius type hybrids making massive gains either. I know
two people who bought a prius. Neither have them now :-)

Darren

dmc wrote:

I can't really see prius type hybrids making massive gains either. I know
two people who bought a prius. Neither have them now :-)


Drivel.

(or doesn't he count?)
I was just thinking about it, and apart from anything else I'm really
not sure I want a car that's optimised for being stopped in traffic...

Andy

(dmc) wrote:
In article ,
Bruce wrote:

Currently hydrogen is produced using electricity, over 80% of which is
generated by burning fossil fuels - therefore generating lots of CO2.

Honda say:

"CO2 emissions related to the production of hydrogen vary by source;
however, well-to-wheel CO2 emissions using hydrogen reformed from natural
gas - the most widely used method of production today - are less than
half that of a conventional petrol vehicle. With the production of hydrogen
from water by electrolysis, CO2 emissions can be further reduced and
ultimately approach zero if the electricity is generated from sustainable
sources, such as solar, wind, hydro and wave power."

which sounds fantastic - but then it would from them wouldn't it

Interesting they don't mention nuclear as an option...


Interesting that they chose to mention natural gas, which is a vanishing
resource, and one whose cost and availability is subject to the whims of
a certain Russian Prime Minister and former President who is soon to be
president again. ;-)

"Dave Baker" wrote in message
...

wrote in message
...
The microcar concept was done to death in britain, they were popular
for many decades, but no more. The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety.

The microcar concept is a million miles from what I'm contemplating here.
Making cars very small and very short is counterproductive in most
respects. Safety, luggage capacity and very importantly it makes it
impossible to generate a low drag shape.

It's nice to have low weight but it's not the major issue, or at least not
worth taking to extremes, especially if you have regenerative braking
(RB). The main issues are frontal area and Cd. So what we need are low,
long, narrow streamlined cars where's still plenty of metal between the
passengers and whatever they might hit at each end.

The Prius actually has many things close to right. It has a very low Cd by
virtue of length and careful streamlining. What it doesn't have right is
frontal area and weight although the RB counteracts much of the downside
of the latter. But, and it's a big but, if the car is heavy the
performance is crap unless the engine is large and that kills low speed
consumption because the engine isn't working efficiently and has high
internal friction.

2000 lbs is not an extreme weight reduction measure. As I said it was a
perfectly normal weight before cars got bloated with safety features. With
modern materials that's plenty to build a decent sized car with but it
must have a lower frontal area than normal to get best consumption.

My target as I said was 2000 lbs, 17 sq ft and Cd of 0.26. That frontal
area only means the car being about 10% narrower and 10% lower than a
Prius. Just a few inches in each dimension. 21 x 0.9 x 0.9 = 17

Now you leave it comparitively long, say normal saloon car length, to
preserve luggage and passenger capacity and help with streamlining. It
would look a little unusual in its proportions but not unduly so. I can
easily conceive of a car weighing much less than 2000 lbs with modern
materials but it's not necessary to go that far.

Packaging could perhaps be a driver in the front with luggage space to his
left, two passengers behind him, maybe two child seats behind those as an
option and the boot space behind that with the spare seats easily
removeable to create a van/estate car. More innovative would be to have
the drivetrain to the left of the driver and more luggage space in the
long streamlined nose/crumple zone as well as in the rear.

Engine could be something like a 70 bhp diesel which would give adequate
if not sparkling performance due to the low weight. 0-60 mph in 12
seconds. A 90 bhp engine would drop that to 9 seconds which is starting to
get reasonably nippy.

This not a city car concept. It's an open road tourer capable of going
long distances with very low fuel consumption. Travel in cities is best
dealt with by other means - electric cars, small cars with RB and public
transport. Top speed would be about 110 mph, a five gallon tank would take
you from London to Aberdeen.

You have just designed a Vauxhall Astra. 8-)

"Doctor Drivel" wrote:
"Bruce" wrote in message
.. .

Thank God none of our buying decisions will be based on your drivel.

I am DR Drivel, I recognise drivel when I see it.


.... when you look in the mirror.

In article ,
Andy Champ wrote:
dmc wrote:

I can't really see prius type hybrids making massive gains either. I know
two people who bought a prius. Neither have them now :-)


Drivel.

(or doesn't he count?)

Ah, of course. Make that 3 people then. Two of which have a brain and have
got rid of them... Dunno if Drivel still has his (assuming he actually had
one and hadn't just sent off for the brochure).

I was just thinking about it, and apart from anything else I'm really
not sure I want a car that's optimised for being stopped in traffic...

I dunno. Would be quite handy for my commute in Canterbury :-(

Darren

In article ,
Doctor Drivel wrote:

"dmc" wrote in message ...
In article ,
Doctor Drivel wrote:

8 year guarantee expected average life = 12 yrs.

Or 100k miles isn't it?...that's less than 8 years for many people

Production? Where can we buy one?

Southern California IIRC

Not that know of.

No, you are correct - it is only available for lease apparantly (at "only"
300 quid a month)

Darren

"dmc" wrote in message ...

The 5,000-psi hydrogen storage tank is slightly scary as well - but then
everyone driving around with a plastic tank containing 10 gallons of
petrol is scary I guess..

If you get a hydrogen leak you end up breathing it in.. its not toxic but
should you see a hydrogen fire travelling towards you at high speed you had
better keep you mouth shut.

It is difficult to think of anything more pointless at this time than a
hydrogen fuel cell powered car. That will change when we have a lot
more power generated by nuclear and renewables. But that won't be for
at least another 15 years.

I can't really see prius type hybrids making massive gains either. I know
two people who bought a prius. Neither have them now :-)

Any person that wanted to make a difference would buy a smaller car.

Dave Baker wrote:
Rather than it get lost in the pointless drivel (dribble?) in the Petrol v
Diesel (Prius) squabble I'll start this new thread.

One of the many programs I've written over the years to help me in my
automotive related business is a spreadsheet which calculates the power and
fuel useage a car requires to travel at a given speed. It takes the weight,
rolling resistance, frontal area and drag coefficient, works out the wheel
bhp and flywheel bhp required at each speed from these and then applies
average BSFC (brake specific fuel consumption) data for both petrol and
diesel engines to calculate the fuel requirement and mpg. You can also enter
the price per litre of each fuel and it will calculate the pence per mile
fuel use.

You can also alter the speed in any of the calculation rows to a new value
and it'll tell you how much power you'll need to achieve that top speed and
what the fuel consumption would then be.

By playing with the car weight and drag data you can find out very quickly
what factors affect power requirement and fuel consumption. Basically weight
affects rolling resistance which is a big factor at low speed but not at
high speed and aerodynamic drag is the reverse. For good economy at low
speed you want a low weight vehicle and at high speed a low drag one.

Using it you can easily see what is needed to design a genuine 100 mpg car.
Low weight, low drag, efficient diesel engine. A 2000 lb car with low
rolling resistance tyres, 17 sq ft frontal area, 0.26 Cd drag (same as a
Prius) should do 110 mpg at 60 mph and 90 mpg at 70 mph with an efficient
diesel engine. For a one or two occupant vehicle this is not a difficult
concept to realise. The average hatchback in the 80s weighed less than that
and many cars such as the Mini have been much lighter.

This morning I've tweaked the program to be more user friendly and added
some guidelines for the data inputs for various cars. It's hosted here.

http://www.mediafire.com/?zk0mkoj41jx


well after a minute of 100% CPU use when I hit that page, and still
unable to download, I think I'll give it a miss, thanks


I take it its some 'green' site designed to burn CPU cycles instead of
carbon?

Steve Walker wrote:
On Wed, 28 Jan 2009 12:47:52 -0000, Dave Baker wrote:

Rather than it get lost in the pointless drivel (dribble?) in the Petrol v
Diesel (Prius) squabble I'll start this new thread.

One of the many programs I've written over the years to help me in my
automotive related business is a spreadsheet which calculates the power and
fuel useage a car requires to travel at a given speed. It takes the weight,
rolling resistance, frontal area and drag coefficient, works out the wheel
bhp and flywheel bhp required at each speed from these and then applies
average BSFC (brake specific fuel consumption) data for both petrol and
diesel engines to calculate the fuel requirement and mpg. You can also enter
the price per litre of each fuel and it will calculate the pence per mile
fuel use.

You can also alter the speed in any of the calculation rows to a new value
and it'll tell you how much power you'll need to achieve that top speed and
what the fuel consumption would then be.

By playing with the car weight and drag data you can find out very quickly
what factors affect power requirement and fuel consumption. Basically weight
affects rolling resistance which is a big factor at low speed but not at
high speed and aerodynamic drag is the reverse. For good economy at low
speed you want a low weight vehicle and at high speed a low drag one.

Using it you can easily see what is needed to design a genuine 100 mpg car.
Low weight, low drag, efficient diesel engine. A 2000 lb car with low
rolling resistance tyres, 17 sq ft frontal area, 0.26 Cd drag (same as a
Prius) should do 110 mpg at 60 mph and 90 mpg at 70 mph with an efficient
diesel engine. For a one or two occupant vehicle this is not a difficult
concept to realise. The average hatchback in the 80s weighed less than that
and many cars such as the Mini have been much lighter.

This morning I've tweaked the program to be more user friendly and added
some guidelines for the data inputs for various cars. It's hosted here.

http://www.mediafire.com/?zk0mkoj41jx

Ok, having force quitted Firefox, be aware that this site has a nasty
scam on it.

Ther is a flash advert that detects your machine and says 'is your
(PC/MAC) running slow' and invites you to spend money to make it go faster.

In fact the code in that advert, is deliberately designed to slow your
machine to a crawl.

I am sure this quattro file is fine, but I will NOT use that website.

On Wed, 28 Jan 2009 12:47:52 -0000, "Dave Baker"
wrote:

http://www.mediafire.com/?zk0mkoj41jx

It's an old Dos Borland Quattro format which is what I've used for donkey's
years for spreadsheet work cos I'm too set in my ways to use newfangled
windows spreadsheets but they should be able to recognise it without any
problem.

It's unreadable with the latest version of OpenOffice and also with
Lotus 123R5 dating back to 1994 that usually copes with everything
else. While there are a number of free converter programs for this
format they all seem to be limited to a very low number of lines and
half a spreadsheet is useless. Have you considered using paper tape
or a Sinclair Spectrum cassette as they are probably more compatible
with modern computers?


--

On Wed, 28 Jan 2009 07:28:10 -0800 (PST), wrote:

The microcar concept was done to death in britain, they were popular
for many decades, but no more.

eh? They were around in the 50's and 60's, mainly abominations and
they were hardly popular.

The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety.

If the Smart 2 seater isn't a practical, safe, microcar then what is?

I know I'd sooner be in a crash in one of those than in a 1960's Mini
or anything of the same era and size produced by Fiat or Renault or
Citroen.


--

In message , Mike
writes
On Wed, 28 Jan 2009 07:28:10 -0800 (PST), wrote:

The microcar concept was done to death in britain, they were popular
for many decades, but no more.

eh? They were around in the 50's and 60's, mainly abominations and
they were hardly popular.

The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety.

If the Smart 2 seater isn't a practical, safe, microcar then what is?

I know I'd sooner be in a crash in one of those than in a 1960's Mini
or anything of the same era and size produced by Fiat or Renault or
Citroen.


I wonder what dennis drives ...


--
geoff

"geoff" wrote in message
...
In message , Mike
writes
On Wed, 28 Jan 2009 07:28:10 -0800 (PST), wrote:

The microcar concept was done to death in britain, they were popular
for many decades, but no more.

eh? They were around in the 50's and 60's, mainly abominations and
they were hardly popular.

The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety.

If the Smart 2 seater isn't a practical, safe, microcar then what is?

I know I'd sooner be in a crash in one of those than in a 1960's Mini
or anything of the same era and size produced by Fiat or Renault or
Citroen.


I wonder what dennis drives ...

Astra 1.7 CDT, Corsa 1.2 or a smart depending on what I am doing and who got
there first.
The Astra always goes first and I spend a lot of time in the Smart.
It uses more fuel than the Astra BTW.

In article
,
Osprey wrote:
Honda has it in production and the sooner it reaches UK the
better .... ZERO emissions .... fuel produced by simple electrolysis
of water - which can be easy & cheap, no expensive & heavy batteries
to run out.

Nice thought, but electrolysis isn't a particularly efficient use of
energy.

--
*Isn't it a bit unnerving that doctors call what they do "practice?"

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Mike wrote:
The microcar concept was done to death in britain, they were popular
for many decades, but no more.

eh? They were around in the 50's and 60's, mainly abominations and
they were hardly popular.

They were fairly popular with those wanting to 'upgrade' from a motorbike
who couldn't afford a proper car. They were very much cheaper new than a
new small car - unlike the Smart.

The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety.

No worse than a motorbike.

If the Smart 2 seater isn't a practical, safe, microcar then what is?

I know I'd sooner be in a crash in one of those than in a 1960's Mini
or anything of the same era and size produced by Fiat or Renault or
Citroen.

Indeed.

--
*Santa's helpers are subordinate clauses*

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
Mike wrote:
The microcar concept was done to death in britain, they were popular
for many decades, but no more.

eh? They were around in the 50's and 60's, mainly abominations and
they were hardly popular.

They were fairly popular with those wanting to 'upgrade' from a motorbike
who couldn't afford a proper car. They were very much cheaper new than a
new small car - unlike the Smart.

The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety.

No worse than a motorbike.


Exactly...


If the Smart 2 seater isn't a practical, safe, microcar then what is?

I know I'd sooner be in a crash in one of those than in a 1960's Mini
or anything of the same era and size produced by Fiat or Renault or
Citroen.

Indeed.

I'd rather not be in a Smart at all.

"Bruce" wrote in message
...
"Doctor Drivel" wrote:
"Bruce" wrote in message
. ..

Thank God none of our buying decisions will be based on your drivel.

I am DR Drivel, I recognise drivel when I see it.

... when you look in the mirror.

Have you been invited top the their meet?

"Andy Champ" wrote in message
. uk...
dmc wrote:

I can't really see prius type hybrids making massive gains either. I know
two people who bought a prius. Neither have them now :-)

Drivel.

I have mine and I like the Mk 3 just come out. Fantastic!!!!