Fiat 900cc TwinAir engine, to be introduced for Fiat 500 at 2010 Geneva Motor Show

Fiat 900cc TwinAir engine, to be introduced for Fiat 500 at 2010 Geneva Motor Show

2009 fiat 500 convertible 500c 2 006

2009 fiat 500 convertible 500c 2 006

Fiat 500 Abarth

Fiat 500 Abarth

2009 Tata Nano

2009 Tata Nano

As we keep saying, one of the ways that automakers will meet more stringent fuel economy regulations is by making smaller engines that work harder.

Now Fiat has one-upped its European competition by announcing it will offer a 900cc turbocharged twin in European models of its Fiat 500 mini-car. That engine won't be fitted to the 2011 Fiat 500 to be offered in the U.S. at the end of the year; it will use a 1.4-liter four.

Fiat and Tata only

The tiny new engine, to be called TwinAir (but unrelated to the global air-filter company also called TwinAir), helps Fiat meet increasingly stringent European limits on carbon dioxide emissions.

The company hasn't released figures, but pledges that TwinAir-equipped Fiat 500s will emit less than 100 grams of CO2 per kilometer.

While two-cylinder engines were common in postwar European small cars, Fiat last offered a twin in 1996 in one model of its Cinquecento mini-car.

Today, only one other carmaker now offers a two-cylinder engine in a production car. That's the 623cc, 33-horsepower twin used in the Tata Nano now on sale in India.

Threes common

Many makers offer three-cylinder engines in European models, with the smallest being an 800cc diesel, developing 45 hp, that is offered in European Smart ForTwo models. Other threes are offered by Chevrolet Mitsubishi, Opel, Subaru, Suzuki, and Toyota, among others.

Fiat's new turbo twin develops 85 hp from its 900cc. When it is introduced at next month's Geneva Motor Show, it will be accompanied by a base 65-hp version and a high-performance 105-hp turbo model as well.

Electrohydraulic variable valves

All three twins use the MultiAir technology Fiat pioneered on its small four-cylinder engines. Compared to an engine with standard valvegear, the electrohydraulic system that varies valve timing not only cuts fuel usage by roughly 10 percent but boosts power as well.

Fiat plans to use the two-cylinder in other small cars it sells in Europe and elsewhere. The engine can run on either gasoline or compressed natural gas (CNG).

[Automotive News (subscription required)]