smart Cars in the US!

<div class='quotetop'>QUOTE(cwerdna @ Feb 15 2007, 02:00 AM) [snapback]390733[/snapback]</div>

I was a physics major in college before getting a engineering degree. F=MA is Newton’s second law. Force, position, velocity, acceleration, work, and energy are all interconnected and all relate back to Newton’s second law. Search for classical mechanics on wikipedia for good explanation and all the equations.

Your equation for kinetic energy is correct but I think you missed my point. I don’t argue that a 5000 lb SUV has more kinetic energy then a 1500 lb Smart, but it doesn’t matter how much kinetic energy an object has if it is brought to a stop slowly. If fact you would be worse off if you were in a 5000 lb SUV and hit another 5000 lb SUV because then even more energy must be absorbed. What matters is how slowly you (the driver) come to a stop. This is where vehicle design and crush zones come into play.

A lighter vehicle is safer than a heavy vehicle because it has less energy to absorb in a crash. It is also safer because it will stop, turn and accelerate better than a heavy vehicle and therefore have a better chance of not crashing.

If weight alone made a vehicle safer then to increase the safety of a car all you would need to do in load it down with lead.

 

I read some time ago the builder was planning on intorducing an EV version. When they SAY such things, and it turns out to be vaporware, it's had to put any stock in what they say.

 

Guys, Consumer Reports imported one from Canada, and drove it for nine months. It's a microbox, with a 23 SECOND 0-60 time that gets 43 MPG on diesel and is uncomfortable to drive.

I hear the gas version gets in the 30's for MPG's.

http://www.consumerreports.org/cro/cars/pa....htm?view=Print

Nate

 

We have a Smart Car Fortwo at a local used dealership for sale. A friend of mine told me about it and I had to check it out. The car appears very small from the outside but is very roomy on the inside. It has a cd player, a/c, power windows, and locks. Talking to the salesman, he mentioned that there were a quite of few of them for sale in Milwaukee and they were getting them from Canada. They were asking $26k for this one.

Edit: If anyone local wants to see one, it is at Goben Cars on Stoughton Rd.

 

<div class='quotetop'>QUOTE(cwerdna @ Jul 31 2006, 06:16 PM) [snapback]295170[/snapback]</div>

The Smart is indeed VERY rigid. See it in action here. One of the unexpected problems: it tends to bounce around after a crash, sometimes into oncoming traffic etc., but it's still impressive.

To limit the forces transmitted to its occupants, much of the work is done inside the car by airbags, smart belt tensioners etc. See a much more boring explanation here.

As for the Smart ForFour: they used to build them here, in the Netherlands and it's essentially the same as the 4-door Mitsubishi Colt , but more expensive. Sales did not go so well, Smart is not doing very well and as part of the restructuring plan the ForFour had to go. Leaving Mitsubishi with a new problem, since they cannot share the cost of building the Colt anymore.

 

<div class='quotetop'>QUOTE(jhinton @ Feb 15 2007, 10:47 AM) [snapback]390986[/snapback]</div>

I absolutely agree that a lighter vehicle (and one w/w lower center of gravity) w/better handling, braking and power/weight ratio has a better chance of avoiding an accident in the first place.

The big problem is what I already outlined, the avg. curb weight of vehicles in the US (4142 lbs for the 2006 model year) is a hell of a lot more than the weight of a Smart ForTwo which is ~1600 lbs. If you're going to be hit by a another vehicle, it's almost a certainty that it will be heavier than a ForTwo. You will most certainly be much worse off to be hit by a 5000 lb. vehicle at a given speed than a 1600 lb. vehicle. That's the problem.

I'd like to see a bunch of tests to see how a 1600 lb. ForTwo holds up against 3600-6000 lb. vehicles in collisions vs. say a 3500 lb. well designed vehicle. The Euro NCAP, NHTSA and IIHS crash tests all are against fixed barriers and they all specifically say that you can only compare them between other vehicles of the same class and similar weights. There aren't any new cars or light trucks sold in the US w/such a low curb weight.

<div class='quotetop'>QUOTE(naterprius @ Feb 15 2007, 11:54 AM) [snapback]391029[/snapback]</div>

Yep, they also had some choice quotes about it in the print version and posted more comments about it at http://blogs.consumerreports.org/cars/smart/index.html and http://www.consumerreports.org/cro/cars/ne...o-406/index.htm.

 

<div class='quotetop'>QUOTE(cwerdna @ Feb 16 2007, 08:24 AM) [snapback]391326[/snapback]</div>

Forget about the "lighter vehicle" part, the other factors can make weight almost irrelevant. Remember this test?

 

<div class='quotetop'>QUOTE(lowlander @ Feb 15 2007, 11:34 PM) [snapback]391328[/snapback]</div>

I've not seen the above clip till now, but Top Gear (if that's where it came from) isn't a show that delivers very factual or accurate info. But besides that, duh, they compared a Lotus Exige which is one of the best handling cars money can buy to ones that aren't sports cars and don't have particularly good handling.

 

<div class='quotetop'>QUOTE(cwerdna @ Feb 16 2007, 04:20 AM) [snapback]391334[/snapback]</div>

Further, who says ANYone has to go into a hellaciously sharp turn at balls out speed?!? Those dummies that do that are simply thinning out the bad gene pool I'm afraid to say.

As for the smart car crumple/crush zones? (I say Four feet as a joke, but) If a car is only 4 feet long, it aint got no crumple zones to absorbe impact. Youtube has a video showing the smart car hitting a crash test wall at about 60mph, and the results? Forget about it. Yea, the passenger department survived, but at a fatal cost to the driver.

 

The myth that small cars are less safe is half true. Small cars are generally less safe for the occupants of that vehicle and safer for the occupants of other vehicles.

Government and insurance crash tests against fixed barriers show that large cars as a group have a small safety advantage over compact cars. SUV's and trucks generally do worse. When a say a small advantage, I mean that many small cars perform better in these test than many large cars. This applies to the front and offset front collision test. These approximate the effect of two vehicles of the same mass colliding.

Of course its more common that in collisions one vehicle weighs more than the other. In these cases the vehicle with lower mass is accelerated (or decelerated) much more than the heavier vehicle. The side impact test pick up on some of this as they ram all tested vehicles with a sled of fixed weight, regardless of the weight of the tested car. It is much harder to find light cars that perform as well as heavier cars in side impact tests.

Still, just as heavy cars protect their occupants better, their mass does so at the expense of drivers and passengers of other vehicles. The difference in mass will reduce the impact acceleration of the heavier vehicle and increase, by a greater ammount, the impact acceleration of the lighter vehicle. The weight difference not only increases the average acceleration of the two vehicles; it also may increase fatalities and serious injuries, which are more often caused by truly high impact accelerations. Anecdotal evidence suggests that many traffic accident fatalities involve collisions between vehicles of very different mass or weight. While some see that since the occupants of the light vehicle suffered they are to blame and label small cars death traps. I feel that the blame falls more on the heavy vehicles and think of them as potential death rams.

Another perspective on this problem is that if one person increases the mass of their vehicle, they win at the expense of others. If everone increases the mass of their vehicle, there is little to no gain to anyone in terms of safety. In this case the loser is the environment. Crash tests show that if everyone drove SUV's instead of cars, the impact protection would be no better (and the rollover protection would suffer). Then, to feel safer, some would then need large SUV's to feel safer. As the number of large SUVs increases, more people would feel they need a large SUV to remain safe. What's next? H1's?

This is part of the reason that I admire and envy the European fuel taxes. It allows people to drive heavy vehicles but helps them feel some of the negative effect this has on others. It also encourages more fuel efficient vehicles and reduced miles driven more naturally and universally than CAFE standards or tax credits for select solutions.
It also helps people internalize the costs of congestion that we impose on everyone when we drive. Finally it funds the cost of the highway and road infrastructure with a more sensible use tax rather than subsidizing it with our income tax, as we do here.

 

yes, the smart for two is recently am seen on the road it is more stylish car on the us roads, The smart car hits the street of America this winter. World travelers out there will probably recognize the mini-vehicle from the streets of Europe, where they can be found navigating narrow alleyways and parking in small spaces.
Here are some links with illustrations you might find helpful: Smart Car Video Collection, with Smart Car Videos

 

Couldn't get directly to NHTSA's site, but they have released their test results.
front driver - 4 stars
front passenger - 3
rollover - 3
side impact - 5 w/ the concern of the door popping open.


Smart gets so-so U.S. safety ratings - AutoWeek Magazine

 

something to keep in mind about frontal crash tests

One should keep in mind that with ALL NHTSA (and IIHS) frontal crash tests, that you can only compare them with other vehicles in the same class and of similar weight. This is mentioned under NCAP FAQs at Safercar.gov

"Can I compare vehicles from different classes? Side crash rating results can be compared across all classes because all vehicles are hit with the same force by the same moving barrier.
Rollover ratings can also be compared across all classes.
Frontal crash rating results can only be compared to other vehicles in the same class and whose weight is plus or minus 250 lbs of the vehicle being rated. This is so because a frontal crash rating into a fixed barrier represents a crash between two vehicles of the same weight. Examples:

• It would not be permissible to compare the frontal crash results of a 4,500 lb SUV with those of a 3,000 sedan (different classes and exceeds the weight requirement).
• It would not be permissible to compare the frontal crash results of a 3,600 lb pickup with those of a 3,400 lb van (meets the weight requirement, but different classes).
• It would be correct to compare the frontal crash results of a 3,400 lb passenger car with a 3650 lb passenger car (same class and meets the weight requirement)."

The Smart fortwo is ~1800 lbs. I can't think of any currently sold mass market cars are that light. Here are some starting curb weights (they go up depending on trim and transmission) of some current vehicles for comparison:
08 Honda Fit: 2432 lbs.
08 Honda Civic sedan: 2628 lbs
08 Toyota Yaris liftback: 2295 lbs.
08 Camry 4 cylinder: 3263 lbs.
08 Hummer H2: 6614 lbs.