[Jasen Betts]

Exactly why do you think car's *aren't* fitted with skinny tyres ?

so they can give a good ride with mediocre suspension.

Bye.
Jasen

 

[Don Klipstein]

so they can give a good ride with mediocre suspension.

I would suspect greater tread area and lower ratio of vehicle weight to
tread area would increase the life of the tread.

If there was not a significant disadvantage of skinny tires (with
higher pressure), then I would think cars would be using them to get the
tire weight down. If a car can lose say 50 pounds or more of weight that
counts almost double during acceleration, it appears to me that city gas
mileage could increase by a significant fraction of an MPG and automakers
would love to do that with at least some of their cars for CAFE purposes.

- Don Klipstein ([email protected])

 

[MooseFET]

I would suspect greater tread area and lower ratio of vehicle weight to
tread area would increase the life of the tread.

It does up to a point.

If there was not a significant disadvantage of skinny tires (with
higher pressure), then I would think cars would be using them to get the
tire weight down.

If you can't sell the car, that is a disadvantage. Car makers put all
sorts of fancy stuff on the outside of cars that increase drag but
improve sales.

There is also a ride quality issue. A thinner tire at higher pressure
makes a low loss spring that without a well designed suspension, would
make the ride bouncier.

 

[JosephKK]

Richard Henry [email protected] posted to sci.electronics.design:

So you drove 70 mph between fillups?

Yep. Cross country runs, 250 to 1000 miles at a crack.

 

[JosephKK]

Eeyore [email protected] posted to
sci.electronics.design:

V8 hybrids ? Don't be so ridiculous.

If US auto makers don't change their ways soon, they'll be out of
business.

Graham

Please look at the proposed 2009 Cadillac Escalade.

 

[JosephKK]

Mark [email protected] posted to sci.electronics.design:

Yep, I think the small batteries and electric motor in the Prius
are there for only 2 reasons..

1) efficency gained by regenerative braking
2) improve the acceleration so the ICE can be smaller also
improving the efficency.

If you had the small ICE without the acceleration boost provided
by
the electrics, the acceleration would be poor and people would
not like the "drivablility".

Intersting to note that a flywheel could provide the same
advantage.

In fact I tend to think of the battery and electric motor in the
Prius is just an electric implementation of a flywheel.

Mark





Mark

Yes, and flywheels bring their own issues with changes yaw, pitch
and roll. There will have to be space for the flywheel to spin not
only during normal driving but the vehicle must not become a hazard
if it rolls over in any direction or spins out.

 

[JosephKK]

Jasen Betts [email protected] posted to sci.electronics.design:

no matter - as long at their axles are rigidly constrained to
point in the exact same direction and the have equal and opposite
rotational momentum.

Bye.
Jasen

Outside the unit there is no stresses, inside the unit there is.
That better be one heck of an axel shaft.

 

[JosephKK]

Michael A. Terrell [email protected] posted to
sci.electronics.design:

DRAG was from the theater when all parts were performed by
males. It
meant: 'DRessed As Girl' The other parts were DRAB, or "DRessed
As
Boy' I worked the stage crew on plays in high school, and the
drama teacher couldn't let a day go by without dumping a lot of
theatrical
history on us, while we were working on the play. BTW, I was the
sound man.


So, if you want to keep her in dresses you DO want her in drag.


--
Service to my country? Been there, Done that, and I've got my
DD214 to prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Thank you sir for explaining that to me.

 

[JosephKK]

default [email protected] posted to sci.electronics.design:

Most of us don't have three phase outlets and it is expensive to
get.
The twelve hours is from a source you'd have at home. Cross
country would be a problem - long extension cords and very
accommodating motel owners.

One alternative to a different class of electrical service might
be super caps or storage batteries that could sip electricity all
day long then pass it to the car in one big gulp.
--

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure
Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup
Service in the World! 120,000+ Newsgroups ----= East and
West-Coast Server Farms - Total Privacy via Encryption =----

This is a case where the flywheel (at hotels / motels) would have
the advantage. Fixed location, plenty of time to spool up and
spool down, and really serious energy per unit volume and weight,
not excessive installation / maintenance costs.

 

[Michael A. Terrell]

Michael A. Terrell [email protected] posted to
sci.electronics.design:


Thank you sir for explaining that to me.

What can I say? My head is full of trivia, collected over the last
55 years. Maybe I should be a contestant on some game show?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Eeyore]

Eeyore [email protected] posted


Please look at the proposed 2009 Cadillac Escalade.

A 6 litre V8 AND 2 electric motors !! ?

Only Americans could come up with something as bizarre as this.

Graham

 

[Robert Latest]

I won "designated driver" one time, and drove this guy's Mercedes 300D.

What a pig! Had horrendous blind spots, and went 0-60 in about 10 minutes. ;-)

Oh, the 300D Great car. I once drove a 200D. Built like a tank, no
acceleration at all, but you could probably plough with it.

robert

 

[MooseFET]

Mark [email protected] posted to sci.electronics.design:











Yes, and flywheels bring their own issues with changes yaw, pitch
and roll. There will have to be space for the flywheel to spin not
only during normal driving but the vehicle must not become a hazard
if it rolls over in any direction or spins out.

I think compressed air is a better way to go.

 

[Don Lancaster]

I think compressed air is a better way to go.

Go for what?


The energy density of compressed air is ludicrously low.
Typically one sixth of lead acid or worse. 15 wh/l is hard to acheive.

The efficiencies of most compressed air motors are much worse than an
ICE. Typically 29 percent or less.

No means of efficiently compressing air is known.
Efficient compression requires isothermal operation, which can only be
approximated by elaborate and costly multi-staging.

The fire service proved all this a century ago after throwing bunches of
engineering at the proglem.

The ONLY thing compressed air has going for it is shop floor
convenience. Hydraulics immediately get substituted when serious tail
twisting or anything remotely approaching efficiency is needed.

See http://www.tinaja.com/glib/energfun.pdf



--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Eeyore]

I think compressed air is a better way to go.

Compressed air power storage is horribly lossy.

Graham

 

[Guy Macon]

Go for what?

The energy density of compressed air is ludicrously low.
Typically one sixth of lead acid or worse. 15 wh/l is hard to acheive.

The efficiencies of most compressed air motors are much worse than an
ICE. Typically 29 percent or less.

No means of efficiently compressing air is known.
Efficient compression requires isothermal operation, which can only be
approximated by elaborate and costly multi-staging.

The fire service proved all this a century ago after throwing bunches of
engineering at the proglem.

The ONLY thing compressed air has going for it is shop floor
convenience. Hydraulics immediately get substituted when serious tail
twisting or anything remotely approaching efficiency is needed.

The ONLY thing?

There are other advantages. With pneumatics the light-load
cycle rate is higher, the piping for distribution doesn't
need to have a return path, and in some clean-room applications
the system can tolerate traces of ultrapure gas leaking into
the working area, but not any sort of liquid.

Hydraulics win for strength, efficiency, positional control,
stiffness, and safety if a pipe or cylinder bursts.

You will never see pneumatics in a bulldozer, and you will
never see hydraulics in a machine that puts CDs into CD
cases. Having worked as a design engineer for both Parker
Hydraulics and SMC Pnuematics, I don't see either of them
cutting into the other's business.

 

[Don Lancaster]

The ONLY thing?

There are other advantages. With pneumatics the light-load
cycle rate is higher, the piping for distribution doesn't
need to have a return path, and in some clean-room applications
the system can tolerate traces of ultrapure gas leaking into
the working area, but not any sort of liquid.

Hydraulics win for strength, efficiency, positional control,
stiffness, and safety if a pipe or cylinder bursts.

You will never see pneumatics in a bulldozer, and you will
never see hydraulics in a machine that puts CDs into CD
cases. Having worked as a design engineer for both Parker
Hydraulics and SMC Pnuematics, I don't see either of them
cutting into the other's business.

And the number of pneumatic combined CD case stuffers and automobiles
currently on the road is....?


--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Rich Grise]

Mark [email protected] posted to sci.electronics.design:

Yes, and flywheels bring their own issues with changes yaw, pitch
and roll. There will have to be space for the flywheel to spin not
only during normal driving but the vehicle must not become a hazard
if it rolls over in any direction or spins out.

Well, that's simple - just put the flywheel's axis vertical. Of
course, you want to make sure that it doesn't lose its structural
integrity, and become a spin bomb. ;-)

And people are supposed to know better than to roll their cars over.

Cheers!
Rich

 

[Spehro Pefhany]

Compressed air power storage is horribly lossy.

Graham

Was that proposed compressed air car debunked? It looked pretty iffy
to me, though compressed air or a hydraulic accumulator might be fine
for a hybrid.

Best regards,
Spehro Pefhany

 

[James Arthur]

It was likely a combination of coincidence and something very wrong
with the car. 22MPG at 55MPH is a horrid milage. This is very like
the leaky fuel line case.

FWIW, I've always gotten about 20% better than EPA-rated fuel economy,
by carefully optimizing my driving.

I had been driving 55 mph, then even 50 mph in an attempt to improve
my Acura's mpg. Careful cross-country measurements show optimum fuel
economy to be 41mpg, which applies from 85 down to 65 mph. Going
slower reduces mpg.

A gearhead pal offered a decent explanation of how providing the
engine with optimum load and RPM by going faster makes my particular
engine more efficient, making up for the windage loss... up to a
point, of course.

Cheers,
James Arthur