Audi has announced that its A3 g-tron hatchback will be able to run for 1300km unrefueled, and despite being powered by an internal-combustion engine (no electric motors here), it could be entirely emissions-free.
There are, of course, a few caveats to that last point. For one, zero carbon emissions can only be achieved if the g-tron is fuelled up on Audi's proprietary e-gas, a compressed natural gas substitute synthesized with the aid of wind-generated electricity.
Also, when the energy consumed by the construction of Audi's specialised e-gas facility is taken into account, the total wheel-to-well CO2 emissions come in at less than 30 g/km.
Still, that's an impressive result considering the complete lack of hybrid electric doo-hickery. Even when run on regular ol' gas, the g-tron's CO2 emissions are a miserly 95 g/km.
The heart of the g-tron is a development of Audi's 1.4 litre turbocharged petrol four, which has had modifications to the cylinder head, turbocharger, fuel injectors and catalyst to enable it to run on both petrol and compressed natural gas (CNG).
Power is modest, with just 81kW and 200Nm. Top speed is 190km/h, while the 0-100km/h sprint takes 11 seconds.
Like most dual-fuel cars, the A3 g-tron is started using petrol power, then switched over to CNG.
When the two carbon-composite gas tanks underneath the boot floor are full, there's enough CNG on board to power the A3 g-tron for 400km.
Once the pressure in the CNG tanks runs low the engine automatically switches over to petrol, giving another 900km of range. All up, the A3 g-tron can travel for up to 1300km when fully fuelled up.
The Audi A3 g-tron will make its debut at the end of 2013, and will be a Europe-only product initially. At this stage, it's unclear if Audi's uber-green A3 g-tron will ever make its way to Australia.