🚀 go-pugleaf

steve@[127.0.0.1] (Stephen  X. Carter) wrote:
>On Wed, 15 Aug 2007 08:49:47 GMT, - <-@-.-> wrote:
>>On Wed, 15 Aug 2007 08:16:02 GMT, steve@[127.0.0.1] (Stephen  X.
>>Carter) wrote:
>>>On Wed, 15 Aug 2007 03:15:58 GMT, - <-@-.-> wrote:

>>>>Nano Carbon technology in the years ahead maybe the answer for petrol
>>>>cars as this brings the weight of a car down from 2 or 3 tonnes to
>>>>only 200kg which saves up to 90% on greenhouse gases.

>>>Reference?

>>ABC.net.au
>>Catalyst last Thursday night program. You might even be able to
>>download the show. Its the last 10 mins.

>Thanks. 

>I think that  "a couple of hundred kgs" is a trifle optimistic - perhaps
>300 or 400 at best.

Even 400kg is optimistic. The "ten times stronger than steel"
doesn't work for the whole car which carries a lot of glass,
plastics, copper, aluminium, magnesium and just a little steel.

The steel shell of a large car body probably weighs in at less than
400kg.  If the carbon could be distributed as well to protect the
occupants and to support the other elements would allow the 400kg to
be reduced down to 40kg. Which is only a 360kg saving reducing the
"2 tonnes" down to 1.6; but not likely anyway.

A medium-sized car weighs in at about 1400kg anyway.

The engine, if made from cast iron, uses that material for its
structural stiffness and thermodynamic properties. An alloy block
already weighs in at about a third of an iron one.

I'm not aware of any successful implementation of gears using carbon
technology so at least the gearbox guts and the differential will
have to be made from steel (typically alloys much stronger than
ordinary steel) in the foreseeable future. Transmission housings
also tend to be alloy or even partly plastic/composite nowadays.
So not much mass to lose there.

Suspension and brake components are next worth considering. And are
already being implemented. But carbon technology is only saving
small increments with trespect to the whole vehicle mass.

Cars are as heavy as they are for two main reasons:
1) customer equipment choices/preferences
2) legislated occupant protection

The aforementioned medium-sized car's kerb mass of 1400kg could be
1000kg if non-essential trim and equipment were deleted across the
range. People who specialise in building "specials" for motorsport
can start a current Golf shape, reinforced with a race cage at under
1000kg.

Car buyers make choices of equipment, usually in ignorance of the
effect on fuel economy. A simple rule of thumb is that every 100kg
of moving car consumes 0.2 litres/100km. That's the order of
magnitude.
-- 
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