"flobert" <nomail@here.NOT> wrote in message
news:867b425qbsr3t7gn8dr7kl4tjhmppqii0s@4ax.com...
> On Tue, 18 Apr 2006 17:01:06 -0700, "Michael Pardee"
> <michaeltnull@cybertrails.com> wrote:
>
>>"John Horner" <jthorner@yahoo.com> wrote in message
>>news:40e1g.2073$sh.1533@trnddc08...
>>> A small high tech turbo-diesel can get the job done better!
>>>
>>> John
>>
>>There is certainly something to be said for turbo-diesels. My new work
>>truck
>>is a Ford with the Cummins 6L TDi. It has shortcomings common to diesels
>>and
>>most marked in TDs: it has to be driven gently when cold to protect the
>>engine, it is noisy and smoky (mostly smoky during warm-up), and even when
>>warm merging into traffic makes me wish I had four feet - one to hold the
>>accelerator down, one to let the clutch up, and two to do the Fred
>>Flintstone thing.
>
> Thats why he said a high-tech one. The cummins and other crap in US
> domestic trucks are OLD designs, at least 10 years behind whats
> available in europe, and filtering into the US. Friend's husband has
> the 7.something cummins in an F250. says the same thing as you. Its
> pretty much the same engine as all through the 80's and 90s.
>
I hear that all the time, but my Swedish friend tells me the diesels in
Europe are the exact same way. Certainly the turbo lag will be identical -
you can't get 20 psi boost from thin air.

Mike

 

On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
wrote:

>flobert wrote:
>
>>>Yes, for a commuter vehicle something like the Fit makes sense, though
>>>the safety aspect concerns me.
>>
>>
>> What safety Aspect. and for that matter, who's safety?
>>
>
>My concern is the safety of the occupant when impacted by the monster
>trucks so many folks consider sensible commuter vehicles.

actually, the disadvantage is often to the bigger one. its not so much
a factor of size of impacting vehicle, as energy anyway. being hit
with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
vehicle at 40mph. They're designed to absor those loads. the bigger
car, however, will have a tendency to go up and over the smaller one,
andwill dissipate the energy more dramatically, lots of rolling etc.
Its another situation where only one side of the equation is
considered. plus, with the big vehicle more liekly to be deflected up
and over, its less energy imparted to the small vehicle.

Small vehicles are also more resistant nowadays. There's the video on
google showing the swatch smart car crashing into a concrete barrier
at wither 40 or 50mph, the drivers cabin is barely touched. This is a
vehicle designed to be as long as a normal car is wide (so you can
park 3 or so nose-in in a standard parallel parking space)

>
>All other things being equal, smaller and lighter is a disadvantage to
>the occupants in a crash.

As I said, thats a misconception based on non-complete examination of
all the componants. Theres a video around that shows this graphically
- a mitsubishi shogun hitting the side of a civic, I think. The shogun
comes off just as bad, as it went up, over and carried on rolling.

>
>John

 

On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
wrote:

>flobert wrote:
>
>>>Yes, for a commuter vehicle something like the Fit makes sense, though
>>>the safety aspect concerns me.
>>
>>
>> What safety Aspect. and for that matter, who's safety?
>>
>
>My concern is the safety of the occupant when impacted by the monster
>trucks so many folks consider sensible commuter vehicles.

actually, the disadvantage is often to the bigger one. its not so much
a factor of size of impacting vehicle, as energy anyway. being hit
with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
vehicle at 40mph. They're designed to absor those loads. the bigger
car, however, will have a tendency to go up and over the smaller one,
andwill dissipate the energy more dramatically, lots of rolling etc.
Its another situation where only one side of the equation is
considered. plus, with the big vehicle more liekly to be deflected up
and over, its less energy imparted to the small vehicle.

Small vehicles are also more resistant nowadays. There's the video on
google showing the swatch smart car crashing into a concrete barrier
at wither 40 or 50mph, the drivers cabin is barely touched. This is a
vehicle designed to be as long as a normal car is wide (so you can
park 3 or so nose-in in a standard parallel parking space)

>
>All other things being equal, smaller and lighter is a disadvantage to
>the occupants in a crash.

As I said, thats a misconception based on non-complete examination of
all the componants. Theres a video around that shows this graphically
- a mitsubishi shogun hitting the side of a civic, I think. The shogun
comes off just as bad, as it went up, over and carried on rolling.

>
>John

 

On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
wrote:

>flobert wrote:
>
>>>Yes, for a commuter vehicle something like the Fit makes sense, though
>>>the safety aspect concerns me.
>>
>>
>> What safety Aspect. and for that matter, who's safety?
>>
>
>My concern is the safety of the occupant when impacted by the monster
>trucks so many folks consider sensible commuter vehicles.

actually, the disadvantage is often to the bigger one. its not so much
a factor of size of impacting vehicle, as energy anyway. being hit
with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
vehicle at 40mph. They're designed to absor those loads. the bigger
car, however, will have a tendency to go up and over the smaller one,
andwill dissipate the energy more dramatically, lots of rolling etc.
Its another situation where only one side of the equation is
considered. plus, with the big vehicle more liekly to be deflected up
and over, its less energy imparted to the small vehicle.

Small vehicles are also more resistant nowadays. There's the video on
google showing the swatch smart car crashing into a concrete barrier
at wither 40 or 50mph, the drivers cabin is barely touched. This is a
vehicle designed to be as long as a normal car is wide (so you can
park 3 or so nose-in in a standard parallel parking space)

>
>All other things being equal, smaller and lighter is a disadvantage to
>the occupants in a crash.

As I said, thats a misconception based on non-complete examination of
all the componants. Theres a video around that shows this graphically
- a mitsubishi shogun hitting the side of a civic, I think. The shogun
comes off just as bad, as it went up, over and carried on rolling.

>
>John

 

In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
<nomail@here.NOT> wrote:

> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
> wrote:
>
> >flobert wrote:
> >
> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
> >>>the safety aspect concerns me.
> >>
> >>
> >> What safety Aspect. and for that matter, who's safety?
> >>
> >
> >My concern is the safety of the occupant when impacted by the monster
> >trucks so many folks consider sensible commuter vehicles.
>
> actually, the disadvantage is often to the bigger one. its not so much
> a factor of size of impacting vehicle, as energy anyway. being hit
> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
> vehicle at 40mph. They're designed to absor those loads. the bigger
> car, however, will have a tendency to go up and over the smaller one,
> andwill dissipate the energy more dramatically, lots of rolling etc.
> Its another situation where only one side of the equation is
> considered. plus, with the big vehicle more liekly to be deflected up
> and over, its less energy imparted to the small vehicle.
>
> Small vehicles are also more resistant nowadays. There's the video on
> google showing the swatch smart car crashing into a concrete barrier
> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
> vehicle designed to be as long as a normal car is wide (so you can
> park 3 or so nose-in in a standard parallel parking space)
>
> >
> >All other things being equal, smaller and lighter is a disadvantage to
> >the occupants in a crash.
>
> As I said, thats a misconception based on non-complete examination of
> all the componants. Theres a video around that shows this graphically
> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
> comes off just as bad, as it went up, over and carried on rolling.


It depends on the type of accident. For example, if it's a high speed
accident on the freeway or interstate, the huge SUVs and pickups could
easily turn over and cause those inside the huge SUVs and huge pickups to
be injured or killed. The small cars such as the Fit would be less likely
to turn over or upside down in such a crash. However, most accidents take
place at low speeds such as in towns and cities--usually at intersections.
In those sorts of accidents--neither vehicle is likely to turn over or
upside down. In those cases, it's more likely that the people inside small
cars such as the Fit will be injured than people inside monster sized SUVs
and monster size pick-up trucks.
Jason

--
NEWSGROUP SUBSCRIBERS MOTTO
We respect those subscribers that ask for advice or provide advice.
We do NOT respect the subscribers that enjoy criticizing people.

 

In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
<nomail@here.NOT> wrote:

> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
> wrote:
>
> >flobert wrote:
> >
> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
> >>>the safety aspect concerns me.
> >>
> >>
> >> What safety Aspect. and for that matter, who's safety?
> >>
> >
> >My concern is the safety of the occupant when impacted by the monster
> >trucks so many folks consider sensible commuter vehicles.
>
> actually, the disadvantage is often to the bigger one. its not so much
> a factor of size of impacting vehicle, as energy anyway. being hit
> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
> vehicle at 40mph. They're designed to absor those loads. the bigger
> car, however, will have a tendency to go up and over the smaller one,
> andwill dissipate the energy more dramatically, lots of rolling etc.
> Its another situation where only one side of the equation is
> considered. plus, with the big vehicle more liekly to be deflected up
> and over, its less energy imparted to the small vehicle.
>
> Small vehicles are also more resistant nowadays. There's the video on
> google showing the swatch smart car crashing into a concrete barrier
> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
> vehicle designed to be as long as a normal car is wide (so you can
> park 3 or so nose-in in a standard parallel parking space)
>
> >
> >All other things being equal, smaller and lighter is a disadvantage to
> >the occupants in a crash.
>
> As I said, thats a misconception based on non-complete examination of
> all the componants. Theres a video around that shows this graphically
> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
> comes off just as bad, as it went up, over and carried on rolling.


It depends on the type of accident. For example, if it's a high speed
accident on the freeway or interstate, the huge SUVs and pickups could
easily turn over and cause those inside the huge SUVs and huge pickups to
be injured or killed. The small cars such as the Fit would be less likely
to turn over or upside down in such a crash. However, most accidents take
place at low speeds such as in towns and cities--usually at intersections.
In those sorts of accidents--neither vehicle is likely to turn over or
upside down. In those cases, it's more likely that the people inside small
cars such as the Fit will be injured than people inside monster sized SUVs
and monster size pick-up trucks.
Jason

--
NEWSGROUP SUBSCRIBERS MOTTO
We respect those subscribers that ask for advice or provide advice.
We do NOT respect the subscribers that enjoy criticizing people.

 

In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
<nomail@here.NOT> wrote:

> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
> wrote:
>
> >flobert wrote:
> >
> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
> >>>the safety aspect concerns me.
> >>
> >>
> >> What safety Aspect. and for that matter, who's safety?
> >>
> >
> >My concern is the safety of the occupant when impacted by the monster
> >trucks so many folks consider sensible commuter vehicles.
>
> actually, the disadvantage is often to the bigger one. its not so much
> a factor of size of impacting vehicle, as energy anyway. being hit
> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
> vehicle at 40mph. They're designed to absor those loads. the bigger
> car, however, will have a tendency to go up and over the smaller one,
> andwill dissipate the energy more dramatically, lots of rolling etc.
> Its another situation where only one side of the equation is
> considered. plus, with the big vehicle more liekly to be deflected up
> and over, its less energy imparted to the small vehicle.
>
> Small vehicles are also more resistant nowadays. There's the video on
> google showing the swatch smart car crashing into a concrete barrier
> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
> vehicle designed to be as long as a normal car is wide (so you can
> park 3 or so nose-in in a standard parallel parking space)
>
> >
> >All other things being equal, smaller and lighter is a disadvantage to
> >the occupants in a crash.
>
> As I said, thats a misconception based on non-complete examination of
> all the componants. Theres a video around that shows this graphically
> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
> comes off just as bad, as it went up, over and carried on rolling.


It depends on the type of accident. For example, if it's a high speed
accident on the freeway or interstate, the huge SUVs and pickups could
easily turn over and cause those inside the huge SUVs and huge pickups to
be injured or killed. The small cars such as the Fit would be less likely
to turn over or upside down in such a crash. However, most accidents take
place at low speeds such as in towns and cities--usually at intersections.
In those sorts of accidents--neither vehicle is likely to turn over or
upside down. In those cases, it's more likely that the people inside small
cars such as the Fit will be injured than people inside monster sized SUVs
and monster size pick-up trucks.
Jason

--
NEWSGROUP SUBSCRIBERS MOTTO
We respect those subscribers that ask for advice or provide advice.
We do NOT respect the subscribers that enjoy criticizing people.

 

On Wed, 19 Apr 2006 09:54:18 -0700, jason@nospam.com (Jason) wrote:

>In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
><nomail@here.NOT> wrote:
>
>> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
>> wrote:
>>
>> >flobert wrote:
>> >
>> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
>> >>>the safety aspect concerns me.
>> >>
>> >>
>> >> What safety Aspect. and for that matter, who's safety?
>> >>
>> >
>> >My concern is the safety of the occupant when impacted by the monster
>> >trucks so many folks consider sensible commuter vehicles.
>>
>> actually, the disadvantage is often to the bigger one. its not so much
>> a factor of size of impacting vehicle, as energy anyway. being hit
>> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
>> vehicle at 40mph. They're designed to absor those loads. the bigger
>> car, however, will have a tendency to go up and over the smaller one,
>> andwill dissipate the energy more dramatically, lots of rolling etc.
>> Its another situation where only one side of the equation is
>> considered. plus, with the big vehicle more liekly to be deflected up
>> and over, its less energy imparted to the small vehicle.
>>
>> Small vehicles are also more resistant nowadays. There's the video on
>> google showing the swatch smart car crashing into a concrete barrier
>> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
>> vehicle designed to be as long as a normal car is wide (so you can
>> park 3 or so nose-in in a standard parallel parking space)
>>
>> >
>> >All other things being equal, smaller and lighter is a disadvantage to
>> >the occupants in a crash.
>>
>> As I said, thats a misconception based on non-complete examination of
>> all the componants. Theres a video around that shows this graphically
>> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
>> comes off just as bad, as it went up, over and carried on rolling.
>
>
>It depends on the type of accident. For example, if it's a high speed
>accident on the freeway or interstate, the huge SUVs and pickups could
>easily turn over and cause those inside the huge SUVs and huge pickups to
>be injured or killed. The small cars such as the Fit would be less likely
>to turn over or upside down in such a crash. However, most accidents take
>place at low speeds such as in towns and cities--usually at intersections.
>In those sorts of accidents--neither vehicle is likely to turn over or
>upside down. In those cases, it's more likely that the people inside small
>cars such as the Fit will be injured than people inside monster sized SUVs
>and monster size pick-up trucks.

says who? go look at some actual accidents E=1/2 MV^2 - no getting
away from it, in an eleastic colision, energyis absorbed by both
vehicles in a ratio determined by their elasticity (which in this case
is the deformation values). The image you paint is based on the rather
more simplistic 'inelastic colission' view taught at schools. real
accidents are not inelastic. Thers no 2 force and simple extrapolation
of energies. A light car will more likely slide on its tyres than a
heavy one, thats energy there, if a cars deflected up, energy there,
and you'll have to get your trig tables out to work out how much. see
it gets plenty complex.

The 'small cars are dangerous' thing isn't so true now as it was 20
years ago. cars are built differently, and have many ifferent design
regs now. If you were in a, ooh, 1980 accord-size car, you're going to
be seriously injured than in a modern small car, like the BMW 'mini'
if both took part in the same accident. cars are not all that stable
as we'd like to think. I'm struggling to remembe the rule of thumb for
rolling a car without a ram, but it evades me. a 2inchh lip will roll
pretty much any car sliding sideways at an initial speed of 40mph, i
remmeber that much. (well, not your long, wide low cars like a zonda
etc.

>Jason

 

On Wed, 19 Apr 2006 09:54:18 -0700, jason@nospam.com (Jason) wrote:

>In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
><nomail@here.NOT> wrote:
>
>> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
>> wrote:
>>
>> >flobert wrote:
>> >
>> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
>> >>>the safety aspect concerns me.
>> >>
>> >>
>> >> What safety Aspect. and for that matter, who's safety?
>> >>
>> >
>> >My concern is the safety of the occupant when impacted by the monster
>> >trucks so many folks consider sensible commuter vehicles.
>>
>> actually, the disadvantage is often to the bigger one. its not so much
>> a factor of size of impacting vehicle, as energy anyway. being hit
>> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
>> vehicle at 40mph. They're designed to absor those loads. the bigger
>> car, however, will have a tendency to go up and over the smaller one,
>> andwill dissipate the energy more dramatically, lots of rolling etc.
>> Its another situation where only one side of the equation is
>> considered. plus, with the big vehicle more liekly to be deflected up
>> and over, its less energy imparted to the small vehicle.
>>
>> Small vehicles are also more resistant nowadays. There's the video on
>> google showing the swatch smart car crashing into a concrete barrier
>> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
>> vehicle designed to be as long as a normal car is wide (so you can
>> park 3 or so nose-in in a standard parallel parking space)
>>
>> >
>> >All other things being equal, smaller and lighter is a disadvantage to
>> >the occupants in a crash.
>>
>> As I said, thats a misconception based on non-complete examination of
>> all the componants. Theres a video around that shows this graphically
>> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
>> comes off just as bad, as it went up, over and carried on rolling.
>
>
>It depends on the type of accident. For example, if it's a high speed
>accident on the freeway or interstate, the huge SUVs and pickups could
>easily turn over and cause those inside the huge SUVs and huge pickups to
>be injured or killed. The small cars such as the Fit would be less likely
>to turn over or upside down in such a crash. However, most accidents take
>place at low speeds such as in towns and cities--usually at intersections.
>In those sorts of accidents--neither vehicle is likely to turn over or
>upside down. In those cases, it's more likely that the people inside small
>cars such as the Fit will be injured than people inside monster sized SUVs
>and monster size pick-up trucks.

says who? go look at some actual accidents E=1/2 MV^2 - no getting
away from it, in an eleastic colision, energyis absorbed by both
vehicles in a ratio determined by their elasticity (which in this case
is the deformation values). The image you paint is based on the rather
more simplistic 'inelastic colission' view taught at schools. real
accidents are not inelastic. Thers no 2 force and simple extrapolation
of energies. A light car will more likely slide on its tyres than a
heavy one, thats energy there, if a cars deflected up, energy there,
and you'll have to get your trig tables out to work out how much. see
it gets plenty complex.

The 'small cars are dangerous' thing isn't so true now as it was 20
years ago. cars are built differently, and have many ifferent design
regs now. If you were in a, ooh, 1980 accord-size car, you're going to
be seriously injured than in a modern small car, like the BMW 'mini'
if both took part in the same accident. cars are not all that stable
as we'd like to think. I'm struggling to remembe the rule of thumb for
rolling a car without a ram, but it evades me. a 2inchh lip will roll
pretty much any car sliding sideways at an initial speed of 40mph, i
remmeber that much. (well, not your long, wide low cars like a zonda
etc.

>Jason

 

On Wed, 19 Apr 2006 09:54:18 -0700, jason@nospam.com (Jason) wrote:

>In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
><nomail@here.NOT> wrote:
>
>> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
>> wrote:
>>
>> >flobert wrote:
>> >
>> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
>> >>>the safety aspect concerns me.
>> >>
>> >>
>> >> What safety Aspect. and for that matter, who's safety?
>> >>
>> >
>> >My concern is the safety of the occupant when impacted by the monster
>> >trucks so many folks consider sensible commuter vehicles.
>>
>> actually, the disadvantage is often to the bigger one. its not so much
>> a factor of size of impacting vehicle, as energy anyway. being hit
>> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
>> vehicle at 40mph. They're designed to absor those loads. the bigger
>> car, however, will have a tendency to go up and over the smaller one,
>> andwill dissipate the energy more dramatically, lots of rolling etc.
>> Its another situation where only one side of the equation is
>> considered. plus, with the big vehicle more liekly to be deflected up
>> and over, its less energy imparted to the small vehicle.
>>
>> Small vehicles are also more resistant nowadays. There's the video on
>> google showing the swatch smart car crashing into a concrete barrier
>> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
>> vehicle designed to be as long as a normal car is wide (so you can
>> park 3 or so nose-in in a standard parallel parking space)
>>
>> >
>> >All other things being equal, smaller and lighter is a disadvantage to
>> >the occupants in a crash.
>>
>> As I said, thats a misconception based on non-complete examination of
>> all the componants. Theres a video around that shows this graphically
>> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
>> comes off just as bad, as it went up, over and carried on rolling.
>
>
>It depends on the type of accident. For example, if it's a high speed
>accident on the freeway or interstate, the huge SUVs and pickups could
>easily turn over and cause those inside the huge SUVs and huge pickups to
>be injured or killed. The small cars such as the Fit would be less likely
>to turn over or upside down in such a crash. However, most accidents take
>place at low speeds such as in towns and cities--usually at intersections.
>In those sorts of accidents--neither vehicle is likely to turn over or
>upside down. In those cases, it's more likely that the people inside small
>cars such as the Fit will be injured than people inside monster sized SUVs
>and monster size pick-up trucks.

says who? go look at some actual accidents E=1/2 MV^2 - no getting
away from it, in an eleastic colision, energyis absorbed by both
vehicles in a ratio determined by their elasticity (which in this case
is the deformation values). The image you paint is based on the rather
more simplistic 'inelastic colission' view taught at schools. real
accidents are not inelastic. Thers no 2 force and simple extrapolation
of energies. A light car will more likely slide on its tyres than a
heavy one, thats energy there, if a cars deflected up, energy there,
and you'll have to get your trig tables out to work out how much. see
it gets plenty complex.

The 'small cars are dangerous' thing isn't so true now as it was 20
years ago. cars are built differently, and have many ifferent design
regs now. If you were in a, ooh, 1980 accord-size car, you're going to
be seriously injured than in a modern small car, like the BMW 'mini'
if both took part in the same accident. cars are not all that stable
as we'd like to think. I'm struggling to remembe the rule of thumb for
rolling a car without a ram, but it evades me. a 2inchh lip will roll
pretty much any car sliding sideways at an initial speed of 40mph, i
remmeber that much. (well, not your long, wide low cars like a zonda
etc.

>Jason

 

In article <neuc42d63a15lf165s348oiichol788uq1@4ax.com>, flobert
<nomail@here.NOT> wrote:

> On Wed, 19 Apr 2006 09:54:18 -0700, jason@nospam.com (Jason) wrote:
>
> >In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
> ><nomail@here.NOT> wrote:
> >
> >> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
> >> wrote:
> >>
> >> >flobert wrote:
> >> >
> >> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
> >> >>>the safety aspect concerns me.
> >> >>
> >> >>
> >> >> What safety Aspect. and for that matter, who's safety?
> >> >>
> >> >
> >> >My concern is the safety of the occupant when impacted by the monster
> >> >trucks so many folks consider sensible commuter vehicles.
> >>
> >> actually, the disadvantage is often to the bigger one. its not so much
> >> a factor of size of impacting vehicle, as energy anyway. being hit
> >> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
> >> vehicle at 40mph. They're designed to absor those loads. the bigger
> >> car, however, will have a tendency to go up and over the smaller one,
> >> andwill dissipate the energy more dramatically, lots of rolling etc.
> >> Its another situation where only one side of the equation is
> >> considered. plus, with the big vehicle more liekly to be deflected up
> >> and over, its less energy imparted to the small vehicle.
> >>
> >> Small vehicles are also more resistant nowadays. There's the video on
> >> google showing the swatch smart car crashing into a concrete barrier
> >> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
> >> vehicle designed to be as long as a normal car is wide (so you can
> >> park 3 or so nose-in in a standard parallel parking space)
> >>
> >> >
> >> >All other things being equal, smaller and lighter is a disadvantage to
> >> >the occupants in a crash.
> >>
> >> As I said, thats a misconception based on non-complete examination of
> >> all the componants. Theres a video around that shows this graphically
> >> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
> >> comes off just as bad, as it went up, over and carried on rolling.
> >
> >
> >It depends on the type of accident. For example, if it's a high speed
> >accident on the freeway or interstate, the huge SUVs and pickups could
> >easily turn over and cause those inside the huge SUVs and huge pickups to
> >be injured or killed. The small cars such as the Fit would be less likely
> >to turn over or upside down in such a crash. However, most accidents take
> >place at low speeds such as in towns and cities--usually at intersections.
> >In those sorts of accidents--neither vehicle is likely to turn over or
> >upside down. In those cases, it's more likely that the people inside small
> >cars such as the Fit will be injured than people inside monster sized SUVs
> >and monster size pick-up trucks.
>
> says who? go look at some actual accidents E=1/2 MV^2 - no getting
> away from it, in an eleastic colision, energyis absorbed by both
> vehicles in a ratio determined by their elasticity (which in this case
> is the deformation values). The image you paint is based on the rather
> more simplistic 'inelastic colission' view taught at schools. real
> accidents are not inelastic. Thers no 2 force and simple extrapolation
> of energies. A light car will more likely slide on its tyres than a
> heavy one, thats energy there, if a cars deflected up, energy there,
> and you'll have to get your trig tables out to work out how much. see
> it gets plenty complex.
>
> The 'small cars are dangerous' thing isn't so true now as it was 20
> years ago. cars are built differently, and have many ifferent design
> regs now. If you were in a, ooh, 1980 accord-size car, you're going to
> be seriously injured than in a modern small car, like the BMW 'mini'
> if both took part in the same accident. cars are not all that stable
> as we'd like to think. I'm struggling to remembe the rule of thumb for
> rolling a car without a ram, but it evades me. a 2inchh lip will roll
> pretty much any car sliding sideways at an initial speed of 40mph, i
> remmeber that much. (well, not your long, wide low cars like a zonda
> etc.

Hello,
I believe that monster sized pick-up trucks and SUVs are more likely to
turn over in a high speed accident than most cars such as the Accord
or Toyota Camry. The reason is simple: The monster size pick-up trucks
and SUVs are "top-heavy". I know that some cars (due to their design
are also "top heavy"-eg Toyota Echo). However, most cars are NOT top
heavy. I should note that some monster size SUV's are NOT top heavy.
For example, the Hummer does not appear to me to be top heavy.
However, most cars are not likely to turn over in a high speed accident
because they are NOT top heavy. Do you see my point?
Jason

--
NEWSGROUP SUBSCRIBERS MOTTO
We respect those subscribers that ask for advice or provide advice.
We do NOT respect the subscribers that enjoy criticizing people.

 

In article <neuc42d63a15lf165s348oiichol788uq1@4ax.com>, flobert
<nomail@here.NOT> wrote:

> On Wed, 19 Apr 2006 09:54:18 -0700, jason@nospam.com (Jason) wrote:
>
> >In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
> ><nomail@here.NOT> wrote:
> >
> >> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
> >> wrote:
> >>
> >> >flobert wrote:
> >> >
> >> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
> >> >>>the safety aspect concerns me.
> >> >>
> >> >>
> >> >> What safety Aspect. and for that matter, who's safety?
> >> >>
> >> >
> >> >My concern is the safety of the occupant when impacted by the monster
> >> >trucks so many folks consider sensible commuter vehicles.
> >>
> >> actually, the disadvantage is often to the bigger one. its not so much
> >> a factor of size of impacting vehicle, as energy anyway. being hit
> >> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
> >> vehicle at 40mph. They're designed to absor those loads. the bigger
> >> car, however, will have a tendency to go up and over the smaller one,
> >> andwill dissipate the energy more dramatically, lots of rolling etc.
> >> Its another situation where only one side of the equation is
> >> considered. plus, with the big vehicle more liekly to be deflected up
> >> and over, its less energy imparted to the small vehicle.
> >>
> >> Small vehicles are also more resistant nowadays. There's the video on
> >> google showing the swatch smart car crashing into a concrete barrier
> >> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
> >> vehicle designed to be as long as a normal car is wide (so you can
> >> park 3 or so nose-in in a standard parallel parking space)
> >>
> >> >
> >> >All other things being equal, smaller and lighter is a disadvantage to
> >> >the occupants in a crash.
> >>
> >> As I said, thats a misconception based on non-complete examination of
> >> all the componants. Theres a video around that shows this graphically
> >> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
> >> comes off just as bad, as it went up, over and carried on rolling.
> >
> >
> >It depends on the type of accident. For example, if it's a high speed
> >accident on the freeway or interstate, the huge SUVs and pickups could
> >easily turn over and cause those inside the huge SUVs and huge pickups to
> >be injured or killed. The small cars such as the Fit would be less likely
> >to turn over or upside down in such a crash. However, most accidents take
> >place at low speeds such as in towns and cities--usually at intersections.
> >In those sorts of accidents--neither vehicle is likely to turn over or
> >upside down. In those cases, it's more likely that the people inside small
> >cars such as the Fit will be injured than people inside monster sized SUVs
> >and monster size pick-up trucks.
>
> says who? go look at some actual accidents E=1/2 MV^2 - no getting
> away from it, in an eleastic colision, energyis absorbed by both
> vehicles in a ratio determined by their elasticity (which in this case
> is the deformation values). The image you paint is based on the rather
> more simplistic 'inelastic colission' view taught at schools. real
> accidents are not inelastic. Thers no 2 force and simple extrapolation
> of energies. A light car will more likely slide on its tyres than a
> heavy one, thats energy there, if a cars deflected up, energy there,
> and you'll have to get your trig tables out to work out how much. see
> it gets plenty complex.
>
> The 'small cars are dangerous' thing isn't so true now as it was 20
> years ago. cars are built differently, and have many ifferent design
> regs now. If you were in a, ooh, 1980 accord-size car, you're going to
> be seriously injured than in a modern small car, like the BMW 'mini'
> if both took part in the same accident. cars are not all that stable
> as we'd like to think. I'm struggling to remembe the rule of thumb for
> rolling a car without a ram, but it evades me. a 2inchh lip will roll
> pretty much any car sliding sideways at an initial speed of 40mph, i
> remmeber that much. (well, not your long, wide low cars like a zonda
> etc.

Hello,
I believe that monster sized pick-up trucks and SUVs are more likely to
turn over in a high speed accident than most cars such as the Accord
or Toyota Camry. The reason is simple: The monster size pick-up trucks
and SUVs are "top-heavy". I know that some cars (due to their design
are also "top heavy"-eg Toyota Echo). However, most cars are NOT top
heavy. I should note that some monster size SUV's are NOT top heavy.
For example, the Hummer does not appear to me to be top heavy.
However, most cars are not likely to turn over in a high speed accident
because they are NOT top heavy. Do you see my point?
Jason

--
NEWSGROUP SUBSCRIBERS MOTTO
We respect those subscribers that ask for advice or provide advice.
We do NOT respect the subscribers that enjoy criticizing people.

 

In article <neuc42d63a15lf165s348oiichol788uq1@4ax.com>, flobert
<nomail@here.NOT> wrote:

> On Wed, 19 Apr 2006 09:54:18 -0700, jason@nospam.com (Jason) wrote:
>
> >In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
> ><nomail@here.NOT> wrote:
> >
> >> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
> >> wrote:
> >>
> >> >flobert wrote:
> >> >
> >> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
> >> >>>the safety aspect concerns me.
> >> >>
> >> >>
> >> >> What safety Aspect. and for that matter, who's safety?
> >> >>
> >> >
> >> >My concern is the safety of the occupant when impacted by the monster
> >> >trucks so many folks consider sensible commuter vehicles.
> >>
> >> actually, the disadvantage is often to the bigger one. its not so much
> >> a factor of size of impacting vehicle, as energy anyway. being hit
> >> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
> >> vehicle at 40mph. They're designed to absor those loads. the bigger
> >> car, however, will have a tendency to go up and over the smaller one,
> >> andwill dissipate the energy more dramatically, lots of rolling etc.
> >> Its another situation where only one side of the equation is
> >> considered. plus, with the big vehicle more liekly to be deflected up
> >> and over, its less energy imparted to the small vehicle.
> >>
> >> Small vehicles are also more resistant nowadays. There's the video on
> >> google showing the swatch smart car crashing into a concrete barrier
> >> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
> >> vehicle designed to be as long as a normal car is wide (so you can
> >> park 3 or so nose-in in a standard parallel parking space)
> >>
> >> >
> >> >All other things being equal, smaller and lighter is a disadvantage to
> >> >the occupants in a crash.
> >>
> >> As I said, thats a misconception based on non-complete examination of
> >> all the componants. Theres a video around that shows this graphically
> >> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
> >> comes off just as bad, as it went up, over and carried on rolling.
> >
> >
> >It depends on the type of accident. For example, if it's a high speed
> >accident on the freeway or interstate, the huge SUVs and pickups could
> >easily turn over and cause those inside the huge SUVs and huge pickups to
> >be injured or killed. The small cars such as the Fit would be less likely
> >to turn over or upside down in such a crash. However, most accidents take
> >place at low speeds such as in towns and cities--usually at intersections.
> >In those sorts of accidents--neither vehicle is likely to turn over or
> >upside down. In those cases, it's more likely that the people inside small
> >cars such as the Fit will be injured than people inside monster sized SUVs
> >and monster size pick-up trucks.
>
> says who? go look at some actual accidents E=1/2 MV^2 - no getting
> away from it, in an eleastic colision, energyis absorbed by both
> vehicles in a ratio determined by their elasticity (which in this case
> is the deformation values). The image you paint is based on the rather
> more simplistic 'inelastic colission' view taught at schools. real
> accidents are not inelastic. Thers no 2 force and simple extrapolation
> of energies. A light car will more likely slide on its tyres than a
> heavy one, thats energy there, if a cars deflected up, energy there,
> and you'll have to get your trig tables out to work out how much. see
> it gets plenty complex.
>
> The 'small cars are dangerous' thing isn't so true now as it was 20
> years ago. cars are built differently, and have many ifferent design
> regs now. If you were in a, ooh, 1980 accord-size car, you're going to
> be seriously injured than in a modern small car, like the BMW 'mini'
> if both took part in the same accident. cars are not all that stable
> as we'd like to think. I'm struggling to remembe the rule of thumb for
> rolling a car without a ram, but it evades me. a 2inchh lip will roll
> pretty much any car sliding sideways at an initial speed of 40mph, i
> remmeber that much. (well, not your long, wide low cars like a zonda
> etc.

Hello,
I believe that monster sized pick-up trucks and SUVs are more likely to
turn over in a high speed accident than most cars such as the Accord
or Toyota Camry. The reason is simple: The monster size pick-up trucks
and SUVs are "top-heavy". I know that some cars (due to their design
are also "top heavy"-eg Toyota Echo). However, most cars are NOT top
heavy. I should note that some monster size SUV's are NOT top heavy.
For example, the Hummer does not appear to me to be top heavy.
However, most cars are not likely to turn over in a high speed accident
because they are NOT top heavy. Do you see my point?
Jason

--
NEWSGROUP SUBSCRIBERS MOTTO
We respect those subscribers that ask for advice or provide advice.
We do NOT respect the subscribers that enjoy criticizing people.

 

On Wed, 19 Apr 2006 13:16:51 -0700, jason@nospam.com (Jason) wrote:

>In article <neuc42d63a15lf165s348oiichol788uq1@4ax.com>, flobert
><nomail@here.NOT> wrote:
>
>> On Wed, 19 Apr 2006 09:54:18 -0700, jason@nospam.com (Jason) wrote:
>>
>> >In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
>> ><nomail@here.NOT> wrote:
>> >
>> >> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
>> >> wrote:
>> >>
>> >> >flobert wrote:
>> >> >
>> >> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
>> >> >>>the safety aspect concerns me.
>> >> >>
>> >> >>
>> >> >> What safety Aspect. and for that matter, who's safety?
>> >> >>
>> >> >
>> >> >My concern is the safety of the occupant when impacted by the monster
>> >> >trucks so many folks consider sensible commuter vehicles.
>> >>
>> >> actually, the disadvantage is often to the bigger one. its not so much
>> >> a factor of size of impacting vehicle, as energy anyway. being hit
>> >> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
>> >> vehicle at 40mph. They're designed to absor those loads. the bigger
>> >> car, however, will have a tendency to go up and over the smaller one,
>> >> andwill dissipate the energy more dramatically, lots of rolling etc.
>> >> Its another situation where only one side of the equation is
>> >> considered. plus, with the big vehicle more liekly to be deflected up
>> >> and over, its less energy imparted to the small vehicle.
>> >>
>> >> Small vehicles are also more resistant nowadays. There's the video on
>> >> google showing the swatch smart car crashing into a concrete barrier
>> >> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
>> >> vehicle designed to be as long as a normal car is wide (so you can
>> >> park 3 or so nose-in in a standard parallel parking space)
>> >>
>> >> >
>> >> >All other things being equal, smaller and lighter is a disadvantage to
>> >> >the occupants in a crash.
>> >>
>> >> As I said, thats a misconception based on non-complete examination of
>> >> all the componants. Theres a video around that shows this graphically
>> >> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
>> >> comes off just as bad, as it went up, over and carried on rolling.
>> >
>> >
>> >It depends on the type of accident. For example, if it's a high speed
>> >accident on the freeway or interstate, the huge SUVs and pickups could
>> >easily turn over and cause those inside the huge SUVs and huge pickups to
>> >be injured or killed. The small cars such as the Fit would be less likely
>> >to turn over or upside down in such a crash. However, most accidents take
>> >place at low speeds such as in towns and cities--usually at intersections.
>> >In those sorts of accidents--neither vehicle is likely to turn over or
>> >upside down. In those cases, it's more likely that the people inside small
>> >cars such as the Fit will be injured than people inside monster sized SUVs
>> >and monster size pick-up trucks.
>>
>> says who? go look at some actual accidents E=1/2 MV^2 - no getting
>> away from it, in an eleastic colision, energyis absorbed by both
>> vehicles in a ratio determined by their elasticity (which in this case
>> is the deformation values). The image you paint is based on the rather
>> more simplistic 'inelastic colission' view taught at schools. real
>> accidents are not inelastic. Thers no 2 force and simple extrapolation
>> of energies. A light car will more likely slide on its tyres than a
>> heavy one, thats energy there, if a cars deflected up, energy there,
>> and you'll have to get your trig tables out to work out how much. see
>> it gets plenty complex.
>>
>> The 'small cars are dangerous' thing isn't so true now as it was 20
>> years ago. cars are built differently, and have many ifferent design
>> regs now. If you were in a, ooh, 1980 accord-size car, you're going to
>> be seriously injured than in a modern small car, like the BMW 'mini'
>> if both took part in the same accident. cars are not all that stable
>> as we'd like to think. I'm struggling to remembe the rule of thumb for
>> rolling a car without a ram, but it evades me. a 2inchh lip will roll
>> pretty much any car sliding sideways at an initial speed of 40mph, i
>> remmeber that much. (well, not your long, wide low cars like a zonda
>> etc.
>
>Hello,
>I believe that monster sized pick-up trucks and SUVs are more likely to
>turn over in a high speed accident than most cars such as the Accord
>or Toyota Camry. The reason is simple: The monster size pick-up trucks
>and SUVs are "top-heavy". I know that some cars (due to their design
>are also "top heavy"-eg Toyota Echo). However, most cars are NOT top
>heavy. I should note that some monster size SUV's are NOT top heavy.
>For example, the Hummer does not appear to me to be top heavy.
>However, most cars are not likely to turn over in a high speed accident
>because they are NOT top heavy. Do you see my point?

I know what you're saying, and again, its very simplified. "top
heavyness" is to the rollability of cars on an impact, what a tennis
ball hitting a wall is to two cars impacting. its a very simplified
and overly basic evaluation.

I'll put it simply, into moresimple terms. a heavier car carries more
energy.
A taller car has a higher center of gravity.

now, in an impact between a large car and a smaller one, the intial
ofrces may be ---> <---
If, however, the surfeaces are not completely perpendicular, and the
collapsing equally uniform, there will be a vertical element to it, as
a proportion of its total energy. I greater vertical energy value (due
tot he greater overall energy value) means a greater rotational moment
about the pivot. The higher the COg, the less of a rotation the
vehicle needs to roll. So, a larger vehicle has a greater energy, and
a higher COG meaning its rollover will be greater than a smaller
vehicle for a given deflection.

Next, add in the physical height. A bigger vehicle has bigger wheels.
Often much greater suspension travel. Its impact sports will impact
higher up on the other vehicle, and thus will ride over. This produces
a greater deflection value for a bigger vehicle.

Bigger deflection, rotating with more energy, and a higher COG = very
liekly to roll in an impact with a smaller vehicle.

Its not rocket science. you just ca't look at it in terms of wooden
blocks for vehciles. you have to look at shapes, energies, and a
step-by-step look throughout the collision. Its like you're watching a
ball hit a baseball bat and thinking ball (small light) hits bat
(bigger heavier) so ball will always come off worst (and go out of the
park) It aint so, its curved, there's all sorts of energy deflections
and transfers. A simplistic model, such as the one you're using is
fine for a very eough estimate. but thats all it is, a very simplistic
ball-park figure. Heck, you rear-end someone, a big factor is their
brakes. if they were applied, a lot more damage is done thn if they're
not, yet your model takes none of that into consideration.

just as a closer, another video clip springs to mind - its of a
security post arangement. one of those powered bollards. Whole thing
was probably about 300lbs all told, for the enetire system. They
tested it by driving a 5ton truck into it at 30mph. Stopped the truck
dead. by your modeling methods, the post should probably have been
napped right off. It was, after all, a lot smaller and lighter. Truck
stopped, bollard was through to between the drivers seat, and the
truck almost ended up on its nose (high cog again) but it stopped it.

In short, its not so much the magnitudes of the energy that make the
difference, its where those energies go.

>Jason

 

On Wed, 19 Apr 2006 13:16:51 -0700, jason@nospam.com (Jason) wrote:

>In article <neuc42d63a15lf165s348oiichol788uq1@4ax.com>, flobert
><nomail@here.NOT> wrote:
>
>> On Wed, 19 Apr 2006 09:54:18 -0700, jason@nospam.com (Jason) wrote:
>>
>> >In article <8flc4218gbpo3sn41i39qhmliqvapj1895@4ax.com>, flobert
>> ><nomail@here.NOT> wrote:
>> >
>> >> On Wed, 19 Apr 2006 04:46:46 GMT, John Horner <jthorner@yahoo.com>
>> >> wrote:
>> >>
>> >> >flobert wrote:
>> >> >
>> >> >>>Yes, for a commuter vehicle something like the Fit makes sense, though
>> >> >>>the safety aspect concerns me.
>> >> >>
>> >> >>
>> >> >> What safety Aspect. and for that matter, who's safety?
>> >> >>
>> >> >
>> >> >My concern is the safety of the occupant when impacted by the monster
>> >> >trucks so many folks consider sensible commuter vehicles.
>> >>
>> >> actually, the disadvantage is often to the bigger one. its not so much
>> >> a factor of size of impacting vehicle, as energy anyway. being hit
>> >> with a 2ton vehicle at a closing speed of 90mph is the same as a 4ton
>> >> vehicle at 40mph. They're designed to absor those loads. the bigger
>> >> car, however, will have a tendency to go up and over the smaller one,
>> >> andwill dissipate the energy more dramatically, lots of rolling etc.
>> >> Its another situation where only one side of the equation is
>> >> considered. plus, with the big vehicle more liekly to be deflected up
>> >> and over, its less energy imparted to the small vehicle.
>> >>
>> >> Small vehicles are also more resistant nowadays. There's the video on
>> >> google showing the swatch smart car crashing into a concrete barrier
>> >> at wither 40 or 50mph, the drivers cabin is barely touched. This is a
>> >> vehicle designed to be as long as a normal car is wide (so you can
>> >> park 3 or so nose-in in a standard parallel parking space)
>> >>
>> >> >
>> >> >All other things being equal, smaller and lighter is a disadvantage to
>> >> >the occupants in a crash.
>> >>
>> >> As I said, thats a misconception based on non-complete examination of
>> >> all the componants. Theres a video around that shows this graphically
>> >> - a mitsubishi shogun hitting the side of a civic, I think. The shogun
>> >> comes off just as bad, as it went up, over and carried on rolling.
>> >
>> >
>> >It depends on the type of accident. For example, if it's a high speed
>> >accident on the freeway or interstate, the huge SUVs and pickups could
>> >easily turn over and cause those inside the huge SUVs and huge pickups to
>> >be injured or killed. The small cars such as the Fit would be less likely
>> >to turn over or upside down in such a crash. However, most accidents take
>> >place at low speeds such as in towns and cities--usually at intersections.
>> >In those sorts of accidents--neither vehicle is likely to turn over or
>> >upside down. In those cases, it's more likely that the people inside small
>> >cars such as the Fit will be injured than people inside monster sized SUVs
>> >and monster size pick-up trucks.
>>
>> says who? go look at some actual accidents E=1/2 MV^2 - no getting
>> away from it, in an eleastic colision, energyis absorbed by both
>> vehicles in a ratio determined by their elasticity (which in this case
>> is the deformation values). The image you paint is based on the rather
>> more simplistic 'inelastic colission' view taught at schools. real
>> accidents are not inelastic. Thers no 2 force and simple extrapolation
>> of energies. A light car will more likely slide on its tyres than a
>> heavy one, thats energy there, if a cars deflected up, energy there,
>> and you'll have to get your trig tables out to work out how much. see
>> it gets plenty complex.
>>
>> The 'small cars are dangerous' thing isn't so true now as it was 20
>> years ago. cars are built differently, and have many ifferent design
>> regs now. If you were in a, ooh, 1980 accord-size car, you're going to
>> be seriously injured than in a modern small car, like the BMW 'mini'
>> if both took part in the same accident. cars are not all that stable
>> as we'd like to think. I'm struggling to remembe the rule of thumb for
>> rolling a car without a ram, but it evades me. a 2inchh lip will roll
>> pretty much any car sliding sideways at an initial speed of 40mph, i
>> remmeber that much. (well, not your long, wide low cars like a zonda
>> etc.
>
>Hello,
>I believe that monster sized pick-up trucks and SUVs are more likely to
>turn over in a high speed accident than most cars such as the Accord
>or Toyota Camry. The reason is simple: The monster size pick-up trucks
>and SUVs are "top-heavy". I know that some cars (due to their design
>are also "top heavy"-eg Toyota Echo). However, most cars are NOT top
>heavy. I should note that some monster size SUV's are NOT top heavy.
>For example, the Hummer does not appear to me to be top heavy.
>However, most cars are not likely to turn over in a high speed accident
>because they are NOT top heavy. Do you see my point?

I know what you're saying, and again, its very simplified. "top
heavyness" is to the rollability of cars on an impact, what a tennis
ball hitting a wall is to two cars impacting. its a very simplified
and overly basic evaluation.

I'll put it simply, into moresimple terms. a heavier car carries more
energy.
A taller car has a higher center of gravity.

now, in an impact between a large car and a smaller one, the intial
ofrces may be ---> <---
If, however, the surfeaces are not completely perpendicular, and the
collapsing equally uniform, there will be a vertical element to it, as
a proportion of its total energy. I greater vertical energy value (due
tot he greater overall energy value) means a greater rotational moment
about the pivot. The higher the COg, the less of a rotation the
vehicle needs to roll. So, a larger vehicle has a greater energy, and
a higher COG meaning its rollover will be greater than a smaller
vehicle for a given deflection.

Next, add in the physical height. A bigger vehicle has bigger wheels.
Often much greater suspension travel. Its impact sports will impact
higher up on the other vehicle, and thus will ride over. This produces
a greater deflection value for a bigger vehicle.

Bigger deflection, rotating with more energy, and a higher COG = very
liekly to roll in an impact with a smaller vehicle.

Its not rocket science. you just ca't look at it in terms of wooden
blocks for vehciles. you have to look at shapes, energies, and a
step-by-step look throughout the collision. Its like you're watching a
ball hit a baseball bat and thinking ball (small light) hits bat
(bigger heavier) so ball will always come off worst (and go out of the
park) It aint so, its curved, there's all sorts of energy deflections
and transfers. A simplistic model, such as the one you're using is
fine for a very eough estimate. but thats all it is, a very simplistic
ball-park figure. Heck, you rear-end someone, a big factor is their
brakes. if they were applied, a lot more damage is done thn if they're
not, yet your model takes none of that into consideration.

just as a closer, another video clip springs to mind - its of a
security post arangement. one of those powered bollards. Whole thing
was probably about 300lbs all told, for the enetire system. They
tested it by driving a 5ton truck into it at 30mph. Stopped the truck
dead. by your modeling methods, the post should probably have been
napped right off. It was, after all, a lot smaller and lighter. Truck
stopped, bollard was through to between the drivers seat, and the
truck almost ended up on its nose (high cog again) but it stopped it.

In short, its not so much the magnitudes of the energy that make the
difference, its where those energies go.

>Jason