I wonder what's the top-speed in all-electric mode.

I'm not keen on the aluminum rails supporting the roof, they remind me of the Citroen Pluriel (whose roof can be removed). They're also incongruous with the overly aggressive front and rear facia. IMHO, this car is trying a little too hard to hide its small size. Then again, they had to differentiate it from VW's rather bland New Small Family (cp. Up! and Space Up! concepts).

Note that Audi chose the same hybrid layout (parallel through-the-road) they used for the original Avant Duo, the first modern production hybrid. Sadly, the battery, power electronics and control systems technology of the day wasn't up to the task and the Duo flopped badly in the German market.

http://en.wikipedia.org/wiki/Audi_100#Audi_Duo

However, PHEV layouts really only make sense for urban runabouts and commute vehicles, which aren't supposed to cost an arm and a leg. Does it really need a 150hp turbocharged ICE? Wouldn't a 50km (30mi) range on grid electricity be quite sufficient in most cases, using cheap carbon foam lead-acid batteries (Firefly) rather than fancy Li-ion units? Plus, with a beefy electric motor to mask torque loss during gear shifts, wouldn't a single-clutch manumatic be good enough?

The mere fact that you have useful range and performance on grid electricity alone *is* the premium. There's no need to go overboard, though I suspect the marketing departments at GM, Volvo, Citroen and Audi are all keen to skim the cream off the top before they take the technology mainstream.

Design is good and concept is also good. Audi was the first to make a Hybrid, but they never brought it to the market.

Is the Lithium battery good now, if so when are they bringing it to market.

i want one!

Raphael:

I agree with you.

The customers should have more options for battery packs, from a low power, lower cost Firefly to the most sofisticated high performance, high cost lithium pack with ultra capacitors. In other words, we should have the choice between PHEV-30, 60 up to 100+ Km. Ideally, the battery pack should upgrable, at a latter date, when cost is down.

I want one too, if it were reasonably priced. 60 miles all-electric would cover almost all my driving. Plus it's not too agro in looks on the one hand while not being too wimpy-looking on the other. Friendly-sporty, not mean-sporty, if you know what I mean. But as Rafael suggests, I'd cut some of the performance to keep the price down.

HenryP: You can cruise at highway speeds with less than 15kw. Here's an interesting article on PHEVs
http://www.americanscientist.org/template/AssetDetail/assetid/54788?fulltext=true&print=yes#54880

@ Henry P -

note that electric motors can be overtorqued for short periods (~30 secs) due to the thermal inertia of the rotor and stator. In other words, an electric motor rated at 30kW = 50hp can actually deliver perhaps 50kW = 80hp for short bursts of acceleration and/or recuperative braking, provided the battery and power electronics can also support that load. Moreover, permanent-magnet motors can deliver close to rated torque at any speed and instantly - an ICE cannot hope to match those dynamics. Acceleration response at low vehicle speeds is what drivers of urban runabouts care about most.

In short, don't directly compare electric horsepower ratings to those for ICEs. In transient situations, which are the norm in light duty vehicle applications, the two are chalk and cheese.

Btw: 30kW = 50hp sustained is about what you need to keep moving at 75mph = 120kph on the freeway. Audi has wisely advertised a top speed of just 100kph on grid electricity alone to avoid excessive wear and tear on the electrical components. Your light duty ICE wouldn't last 150,000 miles either if it were always driven at or near peak load.

@ Patrick -

sorry, you're right. I had miscalculated on the conversions.

Thermal inertia simply refers to the time it takes for a mass to heat up. Electric motors aren't 100% efficient, some of the energy is dissipated due to ohmic resistance and eddy currents induced by the fluctuating magnetic field strength. Many traction motors feature a cooling fan.

Overtorqueing an electric motor means increasing the current to levels that will cause the windings to self-heat faster than they can be cooled. Do it for too long and the wires or rather, the insulation around them, melts. This destroys the motor.

30kW sustained is about what you need to keep moving at 75mph = 120kph on the freeway.

A small car needs only about half that on level highway with no wind, but long highway grades can easily triple the road load.

The idea of 100 km pure EV range with a 30 kW motor is silly, though. Even with overtorque the power is simply insufficient for highway merging, gradability, etc. The ICE will kick on for all but the most benign driving, just as it does in Prius PHEV conversions. And, as you note, the ICE in this concept car is oversized -- 110 kW electric and 30 kW ICE would make more sense.

I think Firefly is a lot more than one year away from their full battery design. A year sounds about right for their first phase.