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The drawing above is an early concept drawing for our production vehicle.
We are revising this drawing to better reflect what the production vehicles will look like. The production
vehicles will look more like the proof-of-concept vehicle, with its hard-edge styling. The other pictures on the page are of our proof-of-concept
(POC) prototype, which serves as a test mule for the systems in the production vehicle. The first (and subsequent) production vehicles will seat 2 (the POC seats one) and will be front wheel
drive. The production chassis is formed of aluminum, and the body panels will be Lexan. The body/chassis of the POC
is a monocoque structure made from aircraft plywood. This technique has been used for aircraft wings (the highly-regarded Bellanca had wood wings), and, of course, for boats. Ken Fry also runs Hooch Boatworks, where he makes kayaks that are about half the weight of production boats, owing to the high strength-to-weight ratio of
plywood (and plywood-cored composites).
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The
headlights and turn signals are behind Lexan windows. Frontal area of the POC is a little less than it will be
in the second set of four prototypes (which will be comfier, and hold two full-sized people). The POC prototype
now has faired-in suspension and wheels -- which adds a little frontal area, but dramatically improves the streamlining, for
a net gain in efficiency.
Interestingly, a round shaft, such as an axle shaft for front wheel drive, has
ten times the drag of a streamlined section of the same size. Therefore, it is more efficient to enclose the suspension
members and drive shafts, than to leave them exposed as is done on, for example, the Aptera. Doing so also allows the
fenders to be mounted securely from the body, instead of bouncing up and down with the wheels as they do in the Aptera.
Reducing the weight of stuff which must move with the wheels over bumps (called unsprung weight) improves both handling and
ride on bumpy roads.
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In
this view of the POC, you can see some of the exposed guts of the vehicle. The upper surface of the "wings"
between the central fuselage and fenders were installed just after this picture was taken.
You can see that the POC has ordinary lead-acid batteries at this point, which work fine for concept
verification, validating actual energy consumption, etc. With these small batteries, it has only a few miles range on
electricity alone, but they have the huge advantage of remarkably low cost: a whopping $88 total!
In the nose is an even smaller (although
slightly more expensive) battery that starts the engine if I need
to recharge the batteries.
Driving this
reminds me of sailing -- it's nicer when the engine is not running. While the silence of running on electricity alone
is great, it is reassuring to know that the car will never be stuck with flat batteries. The engine provides a level
of freedom and security lacking in a battery-only electric car -- but for most commuting routines the engine will rarely or
never come into play. No matter what the range
of a battery-only electric vehicle, there will be times when you need a few miles more. The Nissan Leaf test results
show that range varies dramatically, all the way down to 45 miles (from the advertised 100) in cold whether and heavy traffic.
Vehicles like the Zing! (and the Chevy Volt) have the huge advantage that if
you want to drive across the country, you can do it. At the same time, driving around town on bateries is more
efficient because the weight of long-range batteries exceeds the weight of the engine/generator. The Chevy
Volt, for example, consumes less electricity per mile than the tiny Tesla Roadster, even though the Volt is a larger vehicle
capable of holding a family. Extended range EVs (GM's
term for plug-in hybrids) offer all the advantages of an electric vehicle, without the range anxiety.
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The disc brakes on the POC are rarely
used. In about five laps of our hilly neighborhood, using regen to maintain speed on the downhill section and to come
to two stops per lap, the friction brakes remained completely cold. Certainly, hard stops and panic stops would
warm up the brakes, but in ordinary driving, much of the stopping energy can be put back into the batteries, rather than wasted
as heat in friction brakes.
Regen is more effective in
a plug-in hybrid (and especially in an extended range EV) than in a standard hybrid like a Prius, because the batttery
pack is much larger and can accept higher charging currents.


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