Super Efficient Cars [very large pictures]

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Post by NeilBlanchard » Mon Sep 08, 2008 12:02 pm

Here's a car that I have missed until now:

Image
Overall height is lowered to 1,200mm, with sleek styling to reduce air resistance. Applying aerodynamics simulation technology, we further optimized the shape of all body parts to thoroughly minimize drag.
The result is possibly the lowest*2 aerodynamic drag coefficient in the world for this class of minivehicle: 0.168, surpassing the 0.19 Cd figure of the UFE-II. Other notable efforts which enhance fuel economy are the composite polymer body and generous use of aluminum to reduce weight to 440kg, and the new 115/65R16 tires, which reduce rolling resistance.

For its power unit, the UFE-III uses a hybrid system comprising an engine and two electric motors. The newly developed 660cc inline 3-cylinder direct injection Atkinson engine offers an outstanding balance of output power, fuel economy, and clean emissions. The electrical generator and drive motors are of the compact, lightweight, highly efficient AC synchronous motor type. Gear shifting is accomplished by a planetary gear mechanism and electrical generator, which function as an electronically controlled continuously variable transmission.
72km/l = 169mpg

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Post by NeilBlanchard » Tue Sep 09, 2008 10:04 am

Hi,

A new model from Toyota, obviously an homage to the Smart Car -- called the iQ:

Image

It front wheel drive, seats up to 3 adults and 1 kid with asymmetrical 3+1 seats -- the front passenger's seat is forwards of the driver's seat, and there is "less" dashboard, too.

[Edit: Some more details on the iQ:

http://autos.yahoo.com/articles/autos_c ... art-Fortwo

Probably will sold in the USA as a Scion model
1L 3cyl gasoline engine -- ~56mpg
1.4L diesel engine -- ~57mpg
~1,900 pounds
9 air bags, including the rear]
Last edited by NeilBlanchard on Wed Oct 22, 2008 12:13 pm, edited 1 time in total.

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higher efficiency engines

Post by NeilBlanchard » Wed Sep 17, 2008 8:16 am

Hi,

Image
(click on image for link to very informative video)
Image
Image
EcoMotors International


This thing looks awesome -- it can be run with just 1 module, or with 2 when you need more power; as each module is fully balanced. It is very efficient --about 40%, and has less heat output.

Another much more efficient IC engine (~39.5%):

Image
Image
Image
http://www.revetec.com/development.htm
http://www.revetec.com/development2.htm
Image
[quote]Another feature of the Revetec engine is that 60% of downward force applied to the main journal via the crankshaft is deflected to rotational force increasing efficiency in the Revetec engine. The image to the left shows the bearings under the piston (Note: The second bearing on the reverse rotating cam is hidden behind the front bearing - side by side). As the piston pushes down on the bearing the load (shown in yellow) forces the trilobe cams to spread. The deflected force is deflected into the opposing counter-rotating trilobe cam. The contact angle between the point of bearing contact (shown in purple) produces the torque lever (shown in red). The trilobe and bearing sizes determine how long the high leverage occurs and is designed for each individual engine characteristic we are wanting to achieve.

The Revetec “trilobateâ€

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Post by NeilBlanchard » Sat Oct 04, 2008 5:42 am

Hello,

Tomorrow evening on "60 Minutes", there will be a segment called "The Race for the Electric Car" which will include the Aptera Typ-1e.

http://www.cbsnews.com/stories/1998/07/ ... 3502.shtml

And for those of you who miss the broadcast, it will likely be available on the Aptera website.

The production design of the Aptera has been settled: they have significantly lowered the chassis by over 4", and they moved the front wheels rearward by about 3-4". They have added exterior mirrors (either to reduce cost and/or meet the letter of California law -- and the video camerasmay still be an option), and they have added rear quarter windows. And a portion of the side door windows is operable. They have also tweaked the aerodynamics, included pushing the windshield forward and up a little -- they claim that it is now more efficient and safer than before, because of these changes.

Here's a comparison of their profiles:
Image

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Post by NeilBlanchard » Sun Oct 05, 2008 9:58 am

Hi,

The new Honda Insight debuts at the Paris Auto Show:

Image
(click on image for link)

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Post by jaganath » Sun Oct 05, 2008 12:21 pm

looks a lot cooler than the old Insight. many people have commented on the roofline similarity between this and the current Prius, but given aero requirements not surprising really.

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Post by aristide1 » Sun Oct 05, 2008 1:26 pm

NeilBlanchard wrote:Here's a car that I have missed until now:

Image

72km/l = 169mpg
Uh, no offense Neil but I would not want to be in that thing when the local roadcrews wait until there's 6+ inches of slush on the highway before they decide to go out and plow. Yes, it's happened to me, every winter around here, and on top of that it's a toll road to boot.

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Post by NeilBlanchard » Sun Oct 05, 2008 5:02 pm

Hi,

On the 60 Minutes show, they let Lutz blither on, when he admits that they don't know how to build an electric for less than $40K -- and even that will be at a loss.

They should have asked for more details from Tesla and/or Aptera -- and they should have mentioned the price and range of the Aptera. Very disappointing CBS and Lesley Stahl.

Here's their site with the video:

http://www.cbsnews.com/stories/2008/...n4502448.shtml

The Mk-1 appears at ~8:04 until 8:21 -- so, yeah 15 seconds, and then they cast doubt about them using electricity from coal...
Some of the other start-ups in California are less conventional, like the all-electric, three-[wheeled] Aptera, due out this Christmas. But one issue with all these cars is that much of the electricity to power them would come from burning coal, which produces greenhouse gases. So they're not necessarily the perfect green solution.
I like the Honda Insight: it has several good aero features: flush upper "grill", narrow and sleek mirrors, a majority of the wheels are actually a flush plastic cover, and the rear spoiler is a pretty crisp. If they do well on the underside, it may actually have a better Cd than the Prius. It is supposed to be lighter weight, and have a more efficient version of the Civic hybrid drive -- and have a base price of $18,500, which is excellent.

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Post by NeilBlanchard » Fri Oct 10, 2008 3:52 am

Hi y'all,

Some good info from Amory Lovins:

http://www.ted.com/index.php/talks/amor ... dgame.html

http://www.oilendgame.com/

Efficiencies that only cost $12/barrel, new lower cost ways to make carbon fiber cars, etc.

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Post by Blue » Fri Oct 10, 2008 9:17 am

NeilBlanchard wrote:I like the Honda Insight: it has several good aero features: flush upper "grill", narrow and sleek mirrors, a majority of the wheels are actually a flush plastic cover, and the rear spoiler is a pretty crisp. If they do well on the underside, it may actually have a better Cd than the Prius. It is supposed to be lighter weight, and have a more efficient version of the Civic hybrid drive -- and have a base price of $18,500, which is excellent.
The Insight design is actually very similar to the 2nd generation Prius. A couple months ago there were "sightings" of Honda testing the Prius and Insight together, and the resemblance was amazing.

The first Prius went on the Japan market in 1997; 2001 in the US. Ever since, Toyota has been improving its Hybrid Synergy Drive (HSD). It's apparently doing well since Toyota has plans to convert their entire fleet over to HSD.

If I had a choice between buying a hybrid that has been proven in the market for over 10 years, versus buying anything else (hybrid, EV, or otherwise) that is green (as in "fresh" or "new"...pun intended!), I would certainly go for experience and reliability. There's nothing worse than taking your shiny new vehicle into the shop every month to get something fixed. With all the new "green" (as in environmentally friendly) designs coming out, I'm reluctant that any of them will stand the test of time.

Although, my opinion is somewhat biased. I've been driving a Prius for over 4 years, and (knock on wood) haven't had any problems.

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Post by NeilBlanchard » Fri Oct 10, 2008 9:57 am

Greetings and welcome to SPCR,

Sure the new Insight looks like the Prius; mainly because the shape is an efficient one for enclosing a car of this size and seating capacity.

But, if the weight of the Honda is (significantly) lower than the Toyota, and all else is similar, then the Honda will be the more efficient car to drive. And hopefully the Honda's lower price is real, and this affects the marketplace.

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Post by Blue » Fri Oct 10, 2008 10:18 am

Thanks Neil. Although, I've been lurking for the past 4 years. :-) Have always admired this site immensely, ever since I was a reviewer/moderator on HTPCnews.com.

I think Honda stands the greatest chance of stealing Toyota's thunder with their Insight. However, I know that Toyota isn't standing by idly. The G3 Prius will be a considerable improvement over the current G2. I just hope that Honda isn't a step behind again (like with the Civic and Accord hybrids), and that they take the new Insight a step farther from the original design (which was always more efficient than the Prius). A lot of people complained when Honda stopped manufacturing the Insight, and it's refreshing to know that they are listening to their customers (as well as the economy...which likely has a bigger influence).

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What all car makers should be doing!

Post by NeilBlanchard » Fri Oct 17, 2008 6:17 am

Greetings,

I want to try to list steps that car makers could/should take to improve the fuel efficiency, in approximate order of cost:

* The most obvious would be to mold the plastic on the front of the vehicle to be smooth and round, with grill openings that are sized (and placed) only as required to cool the engine. Some new plastic bumper covers and grill pieces could be snapped onto cars. Flush covers should be used on all lights. Fairing pieces could be added to side mirrors. "Zigzag" window trim covers (would smooth out turbulence), and hood gap gaskets, and streamlined wheel covers are easy, too.

All these improvements (above) can add at least 10% and as much as 25% to the fuel economy. Here's more:

* Sealing all the seams and joints (with gaskets or backing flanges) in the high pressure areas of the vehicle.

* Smooth floor pans with no sharp protrusions -- this is part of the drag just as much as the parts of the car that can be easily seen.

* Transmission ratios should be optimized for efficiency at normal driving speeds. Higher gearing with 6-7 speeds would be optimal (smaller engines need more gears to work efficiently); or CVT transmissions.

* Narrower and lighter, LRR tires should be used.

* Average & "instant" MPG displays, that are on all the time. (The Scion xD uses the same display for the odometer, the two trip odometers, average MPG, instant MPG -- way too many things on one display! You have to toggle through them with a button that could not be a bigger pain to press...)

* Throttle control (rather than cruise/speed control!) that maintains even throttle in a user-set speed range, with minimal throttle increases to maintain the speed in that range.

* Tire pressure monitor, that warns the driver when the tires get below the recommended pressure (which could be adjusted upwards if the driver wants to run a pressure up to the tire sidewall maximum).

* Efficient and effective fresh air flow through the vehicle, with intakes on a high pressure area, and exhaust vent(s) out the back of the vehicle into the low pressure wake zone, to reduce drag as much as possible.

* On defrost mode, the A/C should only come on automatically at maximum defrost(if at all), and it should always be toggled on/off by the driver. I would prefer to make A/C on the defrost setting optional.

* Fully ducted engine cooling system, with the intake down low on the front, and the exhaust flows into a low pressure zone; minimizing the size of the radiator and the reducing the "internal" drag as much as possible.

* Video cameras and screens in place of side mirrors.

* Automatic engine shut off and start up; at least with CVT (or automatic) transmissions -- and possibly with standard shifts, based on having both the clutch and the brake applied?

* Lean burn in low vacuum conditions.

* Store hot coolant in a vacuum insulated tank, to speed up warm-up time; a-la what the Prius does.

* Coat all the window glass to exclude as much heat as possible.

* Tighten up wheel openings, and always use aerodynamically designed wheels/covers, with rear wheel skirts (at least optional).

* Make roof racks removable. Years ago, I saw a "papoose" add-on storage system that locked onto the back of the car, with a single caster wheel to support the weight -- it tucked completely into the air flow behind the car; and it would be a great way to add storage space when needed; that did not affect how you drove very much. It could actually greatly improve the overall aerodynamic drag of the vehicle.

* For new 4-cylinder engine designs, the crankshaft could be split with a hydraulic coupling that can automatically disengage two cylinders completely; saving all the pumping and friction losses, for situations when 2 cylinders are enough to provide the required torque to move the vehicle.

* Nissan is (supposedly) going to reduce their cars weight by an average of 15%. I think all cars could be reduced by 20-30% with smarter steel fabrications, smarter use of materials. Here's a site that shows a steel chassis that is 25% lighter and nearly twice as stiff/strong as a conventional steel chassis:

http://www.bluescopesteel.com.au/go/new ... ab-project

* * Or, make every vehicle with a plug-in electric w/ serial hybrid ICE drive train, with regenerative braking.

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Post by spookmineer » Fri Oct 17, 2008 4:37 pm

Almost all of these suggestions make sense, but some of them affect the safety of a car:

* Narrower tires will decrease the grip of a car. There most likely is an optimum which points to narrower tires than what cars have these days, but obviously the days of T-Ford tires are over.

* Tire pressure: also an optimum is needed. Increasing pressure lowers gas consumption, but decreases grip.

A lot can be done to improve fuel efficiency, but it should never affect the safety of a car.

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Post by NeilBlanchard » Fri Oct 17, 2008 7:21 pm

Hiya,

All else being equal, narrower tires give plenty of grip. They have less frontal area, and have lower rolling resistance. I run my tires at 38PSI, which is well above the recommended 29PSI, and well below the sidewall max of 44PSI. I have more than enough grip.

Ideally, an efficient car will weigh less, and so the tires don't need to be supporting as much weight, and so they can be narrower. Lighter weight tires "pay back" more than weight savings elsewhere in the car: you have to spin the tires and move them forward, so you gain twice as much by saving weight in the wheels and tires.

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Post by aristide1 » Wed Oct 22, 2008 8:28 am

NeilBlanchard wrote:Hiya,

All else being equal, narrower tires give plenty of grip. They have less frontal area, and have lower rolling resistance. I run my tires at 38PSI, which is well above the recommended 29PSI, and well below the sidewall max of 44PSI. I have more than enough grip.
That's easy for new tires, wait until half the tread is gone and it's raining.

By running your tires that high don't they wear out in the center prematurely? Tire manufacturing is also using natural resources, and my money as well. Otherwise I'd be running around on 4 space saving spares that have like 60 psi.
NeilBlanchard wrote:Ideally, an efficient car will weigh less, and so the tires don't need to be supporting as much weight, and so they can be narrower. Lighter weight tires "pay back" more than weight savings elsewhere in the car: you have to spin the tires and move them forward, so you gain twice as much by saving weight in the wheels and tires.
I wouldn't put the gain of lighter tires that high, and there are other factors, like rolling resistance, which will vary with tread compound.

My last OEM tire was a Bridgestone RE-92, one of the worst I have had to endure, but it probably saved me some gas. The compromise for me was not satisfactory. Their lifespan was poor and wore strangely.

Weight reduction through a tire change is not that great. Far larger weight reductions to unsprung mass occur when switching from steel to aluminum rims. I have never heard a person make this change and proclaim they noticed better mileage. Of the tires I looked at weight varied no more than +- 3 pounds, with +-2 pounds being the norm (all the same size). Granted the tire weight reduction is furthest away from the center of the spinning mass.

You can overdo that light weight car business as well. Plenty of micro cars in Europe under a ton. Are they deathtraps on highways? You don't even have to take this scenario to such an extreme. You can look at your insurance rates as cars get really small. They rise, often offsetting more than your savings in gas. I see no point in robbing Peter to pay Paul, and increasing my risk of injury or death in the process.
Last edited by aristide1 on Wed Oct 22, 2008 12:15 pm, edited 3 times in total.

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Post by NeilBlanchard » Wed Oct 22, 2008 12:08 pm

Hi Aris,

My tires are wearing fine, and from the folks I hear from on EcoModder.com, and ApteraForum.com normal tires today do not wear in the middle under higher pressure -- probably because of the steel belt in the tread?

And light weight cars that are strong, with well designed crumple zones are very safe. Light weight cars that hit a stationary object are much better off, all else being equal, than a heavier car.

A heavy car that doesn't have good crumple zones is more dangerous than a light car with good crumple zones. Check out the Amory Lovins TED video on this:

http://www.ted.com/index.php/talks/amor ... dgame.html

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Post by aristide1 » Wed Oct 22, 2008 12:27 pm

NeilBlanchard wrote: And light weight cars that are strong, with well designed crumple zones are very safe. Light weight cars that hit a stationary object are much better off, all else being equal, than a heavier car.
Looking at Euro micro cars and even some Scion models, when a rear passenger is present, there appears to be just a few inches from the back of the head to the rear bumper (of no value at all at a decent speed). So the question there is - what crumple zone?
NeilBlanchard wrote: A heavy car that doesn't have good crumple zones is more dangerous than a light car with good crumple zones. Check out the Amory Lovins TED video on this:

http://www.ted.com/index.php/talks/amor ... dgame.html
No dispute, but I look at a Smart car and I ask this; the crumple zone is very small and the pasenger area is very stiff. If the stiff cage area stops very suddenly that does not mean that the passengers stop as well. Also - everything you say works for the most part if the Smart car hits a brick wall, but what if it has a head-on with a Jeep Wagoneer? You'd be surprised how many Jeeps there are in Europe. Notice I didn't even mention the Hummer - oops.

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Post by aristide1 » Wed Oct 22, 2008 12:50 pm

spookmineer wrote:Almost all of these suggestions make sense, but some of them affect the safety of a car:

* Narrower tires will decrease the grip of a car. There most likely is an optimum which points to narrower tires than what cars have these days, but obviously the days of T-Ford tires are over.
Narrower tires are preferred on snow and especially ice. Super wide tires need well designed groove patterns to prevent hydroplaning, and even then when they wear that becomes an issue.

There was also an experiment where a car was outfitted with dual skinny tires at all wheels. It looked strange, and it was costly, but it had exceptional dry and wet handling.

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Post by jaganath » Wed Oct 22, 2008 2:12 pm

No dispute, but I look at a Smart car and I ask this; the crumple zone is very small and the pasenger area is very stiff. If the stiff cage area stops very suddenly that does not mean that the passengers stop as well.


is it an achievement to turn stating the obvious into an art form? yes, of course they stop. that's what airbags are for. also the SMART is a city car, the % of its life spent at more than ~40mph will be single figures (the gridlocked traffic of most big european cities sees to this). of course, in your hypothetical example, where our maniac Smart driver barrels into a Jeep Waggoneer head-on at 100mph, it's certain death. why does the more nimble Smart driver not just avoid the collision? why is he going so fast anyway?

Looking at Euro micro cars and even some Scion models, when a rear passenger is present, there appears to be just a few inches from the back of the head to the rear bumper (of no value at all at a decent speed). So the question there is - what crumple zone?


you'll have to be more specific. with the Smart car, there is no rear passenger seat to speak of. with stuff like the Yaris/Aygo, they have at least as much protection for the rear passengers as the front.

you seem preoccupied with harping on about the fact the Smart/other micro cars will not withstand a direct nuclear strike (or the automotive equivalent). most cars go through their entire life cycle without being involved in so much as a minor shunt. obviously the designers of the Smart car could have put 3 feet thick steel slabs on every available body panel to please those who would clearly rather be driving a Porsche Cayenne or Audi Q7 anyway, but that wouldn't be very smart now would it? everything is a tradeoff, more weight, more safety gear, more home comforts = worse fuel consumption, more costly, worse performance. so you have to make a compromise (or those of us not driving about in overstuffed armchairs do anyway): do we want the nippy, economical car which may be slightly less safe (although you could have the safest car in the world, with a dangerous or careless driver it's worth absolutely nothing), or the heavy, lumbering, ladder-framed carcass pooped out by GM et al? I would argue a SMART car driven by someone who has taken a course in advanced/defensive driving is many times as safe as an SUV driven by Joe Average.

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Post by aristide1 » Wed Oct 22, 2008 2:51 pm

I'm just trying to make 2 points:

1. Driving something that small in this country, if you hit another vehicle or they hit you, the other vehicle almost certainly will be larger. And we have deer as well. Hell I've hit 3 of them. And by the way on #2 the airbag deployed and after it deploy the car and myself were doing about 50mph in circles.

2. There's no free lunch.
(although you could have the safest car in the world, with a dangerous or careless driver it's worth absolutely nothing),
That would address:
3. We probably some of the least trained drivers in the world, probably ranking quite high in cell phone self-absorption as well.
you'll have to be more specific.
Are you serious? There are so many cars out there where if the back seats had headrests they would up against the rear glass. The seat backs are at the very edge of the rear of the car. So, what crumple zone?
Last edited by aristide1 on Wed Oct 22, 2008 3:11 pm, edited 1 time in total.

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Post by spookmineer » Wed Oct 22, 2008 3:09 pm

I don't agree [jaganath].

With a large car, most of the front (up until the cage where the passengers are) will function as a crumple zone. The shorter the car, the shorter the crumple zone.
This is a bit hypothetical/theoretical but it explains what I mean (or I hope it does):
The length of the crumple zone defines the potential stiffness of a spring, if the cage is not to be affected.
A car with a nose twice the length of a small car will have twice the deceleration distance. The "spring" to come to a complete stop is twice as long, and deceleration halfs.

Mass is important in crashes, the heavier car does have an advantage. Shoot two pool balls at eachother at the same speed, they will bounce back with equal speed. Shoot two pool balls at eachother where one is significantly heavier, the heavier ball will not bounce back as much as the lighter one does, it might even travel forwards after they hit.

In car physics: two cars equally heavy hit head on, driving the same speed. They come to a stop where the two cars first came in contact with eachother.
A crash with a heavy and a small car: the light car will stop behind where the two cars met, because the heavy car pushed it there during the crash.
A heavy car will therefor have an "extra spring length" because of its weight, making for a softer crash. The light car however comes to a full stop and then is pushed backwards by the heavy car.
As long as there are Audi Q7's driving around I will not take a chance (however slight) to hit one when I'm in a small car.

Even when the passenger cage is still intact, the impact of a crash has an effect on the ones inside it, those G forces aren't kidding. It makes more sense to pick a Prius than a Smart.

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Post by NeilBlanchard » Wed Oct 22, 2008 7:06 pm

Hi,

The Toyota iQ has 9 air bags, including one in the rear. It also has a 5 star crash rating in Europe.

As mentioned in the Amory Lovins TED video, a car made out of very lightweight and strong materials can be big and light at the same time. F1 cars (~1,400 pounds) survive tremendous crashes, and so do NASCAR cars (~3,500 pounds).

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Post by aristide1 » Thu Oct 23, 2008 5:52 am

NeilBlanchard wrote:... F1 cars (~1,400 pounds) survive tremendous crashes, and so do NASCAR cars (~3,500 pounds).
Again, there's no free lunch. Who could afford such cars? I think Mercedes has one model where the frame is carbon fiber, good weight savings at about $200,000. Beyonce drives one.

Usually racers are all traveling in the same direction, are highly skilled drivers, are NOT texting messages, and the road is clear of animals.

When one of those cars does hit a wall look at what happens. How much of the safety of a NASCAR car comes from the added roll cage, the 6 seat point belt? Are the doors welded shut? How would grandpa or grandpa get in/out of such a car? As spookmineer mentioned could the average person handle the G-forces involved? Let alone someone who's frail.

I won't even address those cars in term of emissions or handling in bad weather.

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Post by NeilBlanchard » Thu Oct 23, 2008 5:57 am

Hi Aris,

The costs of carbon fiber are coming down, and again, referring to the TED video by Amory Lovins:

http://www.ted.com/index.php/talks/amor ... dgame.html

The number of components in the chassis is reduced, and can be easily assembled, and color can be added in far fewer steps than with steel. Toyota's 1/X concept car seats four, and has a curb weight of 926 pounds.

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Post by aristide1 » Thu Oct 23, 2008 7:53 am

My question then is would steel be preferable because it is more malleable? Isn't carbon fiber more brittle?

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Post by NeilBlanchard » Thu Oct 23, 2008 6:06 pm

Hi Aris,

Carbon fiber is much stronger by weight, and yes the failure mode is quite different. So, because it is so light, you do a lot to design it so it absorbs a lot of punishment and still you can save a lot of fuel, because you are moving less weight.

Strength and design saves lives. If you can achieve these with light weight, then you also save fuel. Carbon fiber is much lighter than steel.

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Post by aristide1 » Thu Oct 23, 2008 6:46 pm

The Pinto, the Audi 5000, the Vega, the Yugo.

Call me crazy but I'm not quite ready to just assume good design.

Sorry. Your points are still valid though.

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Post by NeilBlanchard » Fri Oct 24, 2008 3:42 am

Hi Aris,

I'm not sure what those cars have to do with our discussion?

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Post by aristide1 » Fri Oct 24, 2008 4:24 am

Just good design is hard work. It may appear initially to be present, but then later it's clear some things were overlooked. For car safety tests are fine, but I will wait and take the insurance company approach, see how many deaths/injuries per accident occur over a year or two.

I'd expect a large emphasis on a Mercedes as far as safety is concerned, I'm less sure other companies will build a car to that standard. I'd be willing to go out on a limb here and say look at the Dodge Neon. It does not fare well in crash tests. Dodge/Chrysler and MB were together for quite some time, and I doubt any MB engineering went into that car. It's most likely the same iffy proposition its always been from a safety aspect. I'd be glad to here I'm wrong about this.

There was a TV special some time back about how seat backs would break during a rear collision. MB deals with this, even when there is no standard or measurement for it. Other car companies do not. If the government created a new safety standard, all the car companies would jump on the bandwagon. Until then.... I admire one thing about MB, when they develop a new safety technique they allow anyone to copy it, they do not patent it and then lock out everyone else. So they claimed in that TV special. (20/20? Dateline? Can't recall.)

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