"Dave Baker" wrote in message
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wrote in message
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The microcar concept was done to death in britain, they were popular
for many decades, but no more. The passenger question isnt really an
issue, one can build cars for any number of people far smaller than
what we have on the road today.

The biggest issue that kills microcars is safety.

The microcar concept is a million miles from what I'm contemplating here.
Making cars very small and very short is counterproductive in most
respects. Safety, luggage capacity and very importantly it makes it
impossible to generate a low drag shape.

It's nice to have low weight but it's not the major issue, or at least not
worth taking to extremes, especially if you have regenerative braking
(RB). The main issues are frontal area and Cd. So what we need are low,
long, narrow streamlined cars where's still plenty of metal between the
passengers and whatever they might hit at each end.

The Prius actually has many things close to right. It has a very low Cd by
virtue of length and careful streamlining. What it doesn't have right is
frontal area and weight although the RB counteracts much of the downside
of the latter. But, and it's a big but, if the car is heavy the
performance is crap unless the engine is large and that kills low speed
consumption because the engine isn't working efficiently and has high
internal friction.

2000 lbs is not an extreme weight reduction measure. As I said it was a
perfectly normal weight before cars got bloated with safety features. With
modern materials that's plenty to build a decent sized car with but it
must have a lower frontal area than normal to get best consumption.

My target as I said was 2000 lbs, 17 sq ft and Cd of 0.26. That frontal
area only means the car being about 10% narrower and 10% lower than a
Prius. Just a few inches in each dimension. 21 x 0.9 x 0.9 = 17

Now you leave it comparitively long, say normal saloon car length, to
preserve luggage and passenger capacity and help with streamlining. It
would look a little unusual in its proportions but not unduly so. I can
easily conceive of a car weighing much less than 2000 lbs with modern
materials but it's not necessary to go that far.

Packaging could perhaps be a driver in the front with luggage space to his
left, two passengers behind him, maybe two child seats behind those as an
option and the boot space behind that with the spare seats easily
removeable to create a van/estate car. More innovative would be to have
the drivetrain to the left of the driver and more luggage space in the
long streamlined nose/crumple zone as well as in the rear.

Engine could be something like a 70 bhp diesel which would give adequate
if not sparkling performance due to the low weight. 0-60 mph in 12
seconds. A 90 bhp engine would drop that to 9 seconds which is starting to
get reasonably nippy.

This not a city car concept. It's an open road tourer capable of going
long distances with very low fuel consumption. Travel in cities is best
dealt with by other means - electric cars, small cars with RB and public
transport. Top speed would be about 110 mph, a five gallon tank would take
you from London to Aberdeen.

You have just designed a Vauxhall Astra. 8-)