tommytoyz wrote in
ups.com:

You are correct about the higher deceleration forces of a lighter
vehicle when it crashes head on with a heavier vehicle, due to the
larger inertia of the heavier one.

The deceleration forces are an extremely important
factor in the survivability of any accident. Consider
that the brain has the consistency of blancmange, and
imagine how easy it is to disrupt internal connections.
Or get an animal's brain from the butchers (if that's
possible any more , and just play around with it.

But it does not mean that the occupants of the heavier are safer, as
their structure may experience more damage,

To some extent more damage to the structure leads
to less damage to the occupants: energy is required
to deform the structure, and that energy then can't
be dissipated in the occupants. That's one essential
reason why car's "crumple zones" are so important.

The worst case would be a light vehicle that
didn't crumple or otherwise absorb energy in
a smooth fashion.

so it's hard to really
tell what would happen and I would say one would have to examine the
overall safety and design of each vehicle,

I certainly agree with that, and I'm sure we both
acknowledge that it is a very difficult topic.

like we compare the sink
measurements of each glider. An ASW 17 for instance is not necessarily
better than an 18 Meter ship, etc....or even perhaps a 15m Diana -2 at
certain speeds.

http://www.bridger.us/2002/12/16/Cra...operVsFordF150

Interesting article. Shows the crumple zone
quite nicely. I'd still looks like that, on
balance, smaller cars fare worse. But there
are notable exceptions - see you next statement.

Size is not all that matters but design.

When size is constant, design matters. When
design is constant, size matters. Which is
more important? I wouldn't like to say. But
all other things being equal (ha!), I'd rather
be in a larger vehicle than a smaller one
(so long as it doesn't roll

Having said that, I drive a "subcompact" car

And yes, I meant brakes.........my bad......

I've never made such a mistake. Never. Oh no.