Fiat has been talking about it for some time; now its new, ultra-frugal, ultra-clean and (relatively) punchy "Twin-Air" two-cylinder micro engine has finally been unveiled at the 2010 Geneva International Motor Show.
Despite a tiny 900cc capacity, the statistics are impressive: 15 per cent more economical and 25 per cent more powerful than a "conventional" 1.2-litre engine, the turbocharged inline two-cylinder is claimed to match the performance of a normally aspirated 16-valve 1.4-litre engine.
The engine is "significantly smaller and lighter than a conventional four cylinder engine." According to the company, it is an "ideal component for hybrid and kinetic energy recovery systems (KERS) and it has been designed for alternative fuels, such as methane."
The Twin-Air engine is designed around what Fiat calls MultiAir technology, the heart of which is -- as the name implies -- in the breathing.
MultiAir, which was first seen on FIRE engines last year, uses an electro-hydraulic valve management system that controls the incoming air via the inlet valves "without using the throttle" -- in a way that reduces emissions while upping performance.
The result is that it will gift the 63kW Twin-Air version of an upcoming Fiat 500 variant with CO2 emissions of just 95g/km -- the lowest, claims Fiat, of any petrol-powered car.
With the turbo kicking in "at very low rpm" to provide strong boost from low speeds, the 0.9-litre engine also benefits from having optimal cylinder displacement in terms of thermodynamic efficiency.
Fiat says the low-friction Twin Air engine has been designed to feel "at least" as smooth as a four-cylinder, via a balancing shaft that maintains "optimal vibration levels in all operating conditions of the engine, from the idling speed to top power."
Twin-Air technology is not a likely contender for Australia though -- largely because our government does not offer the "significant" tax breaks available to manufacturers with low-CO2 cars on European markets. Fiat says the lack of incentives would make a Twin-Air 500 too expensive for Australia.
Read the latest Carsales Network news and reviews on your mobile, iPhone or PDA at www.carsales.mobi