Fiat thinks small and clean with 900cc unit

Fiat is taking downsizing to a new level with the introduction of its new two-cylinder TwinAir engine, a 900cc unit that makes its first appearance in Europe in July under the bonnet of the Fiat 500.

The 65kW powerplant will be the only two-cylinder engine available in a car in Europe. Indian carmaker Tata Motors uses a 25kW/623cc two-cylinder engine in the Nano microcar in India.

Carmakers are removing cylinders and lowering the displacement of their engines to meet tougher CO2 emissions rules that take effect in Europe in 2012.

Fiat is expected to release the TwinAir's official CO2 performance information when it unveils the engine at next week's Geneva motor show.

For the moment it is saying only that the 500 minicars sold with the engine will produce less than 100 grams per kilometre of the greenhouse gas.

The greenest version of the 500, the PUR-02 equipped with a standard stop-start system, currently emits 113gr/km.

The TwinAir engine is a key part of Fiat brand's aim to remain Europe's leader when it comes to fleet CO2 emissions.

Fiat brand had average CO2 emissions of 129gr/km in the first half of last year, according to British market researcher JATO Consult.

That puts it ahead of Toyota, which had fleet emissions of 132.9gr/km during the same period.

Internally called SGE, for Small petrol Engine, the TwinAir has Fiat's fuel-saving MultiAir technology. MultiAir improves power and cuts fuel consumption by 10 per cent with electrohydraulic variable valve timing.

Fiat chose the TwinAir name to because this is the first application of MultiAir technology on a two-cylinder engine.

In terms of capacity, Fiat's TwinAir is the smallest petrol engine available in Europe. Mercedes-Benz unit Smart's ForTwo minicar offers Europe's lowest-displacement engine, a 34kW 799cc three-cylinder diesel.

Rivals such as Volkswagen AG started developing a two-cylinder unit for its new Up family of minicars, but decided to continue using the group's petrol and diesel three-cylinder engines.

Chevrolet, Citroen, Daihatsu, Mitsubishi, Opel/Vauxhall, Peugeot, Subaru, Suzuki and Toyota also offer three-cylinder engines in Europe.

Fiat has a long tradition of two-cylinder engines. Its first appeared as a 10kW 569cc unit in the 1936 Topolino.

A 10kW 479cc unit was used in the 500 that arrived in 1957 and the last two-cylinder engine built by Fiat was the 23kW 704cc unit offered on the Cinquecento minicar from 1991 to 1996.

In addition to the 65kW TwinAir that debuts in Geneva, there will be a turbocharged 78kW version and a 48kW naturally aspirated variant of the engine.

Fiat will add the TwinAir engine to other minicars, beginning with the successors to the Fiat Panda and Lancia Ypsilon minicars. Both replacements are due in the second half of next year.

The TwinAir, which is designed to run on petrol or compressed natural gas, will be built at Fiat Powertrain Technologies' plant of Bielsko Biala, Poland.