[ExI] fuel economy vs danger

[BillK]

On 4/6/10, Rafal Smigrodzki  wrote:
> ### Ceteribus paribus, heavier cars stop later which is a feature, not
>  a bug. In a collision with an object of relatively low mass (such as
>  another car), it is better to be the relatively heavier car, since
>  your deceleration will be much less extreme than the deceleration of a
>  person in the relatively lighter car. A semi will decelerate little
>  while smashing a Hummer to smithereens, and these smithereens could
>  still smash an econobox.
>
>  This leads to an interesting thought: What kind of equilibrium
>  regarding prevalent car weights would form if there was no state
>  interference with human desires? How many would opt for driving
>  Bradleys? How many would rather save the gas money and go for the
>  nimbleness of an Exige?
>
>  Since head-on collisions are uncommon, the actuarial incentive to
>  spend on a Bradley would not be that large but the cool factor would
>  attract some users. Certainly, driving while free (i.e. stateless)
>  would be an interesting experience.
>
>

Braking distance mostly depends on the capacity of the brakes and
friction of the tyre contact patch on the road.

Big cars plus big tyres plus big brakes should (in theory) stop in a
similar distance to small cars with smaller tyres and smaller brakes.
A small car with *big* brakes (discs all-round) and ABS should have
the shortest stopping distance. Car mags have run tests of 0 to 100
and back to 0, and small, light cars with big engines and big brakes
win hands down.

I don't think the dreaded government is much concerned about the size
of car you drive.  It is cost that is the main driver (!) of choice.
Fuel costs money and will cost more as oil becomes scarce. Smaller
cars use less fuel.
Insurance and maintenance costs also increase as cars get more
powerful and expensive to repair. Smaller cars are cheaper to insure
and service.

BillK