The 85hp is a turbo too, just offering lower power than the 105.
This engine will be lighter than the Diesel; it comes in under the 100g/km threshold for tax, which the Fiat Diesel doesn't - why not when the same engine in the Corsa does! - and petrol is cheaper than Diesel fuel, so overall it will be cheaper to run and better handling, with practically identical performance to the Diesel. In fact, looking at the figures, to all intents and purposes it supersedes the 1.2, the 1.4 and the 1.3 Diesel 95. It will be lighter, cheaper to run and better handling than all of them.
Fiat's long term plan is to completely replace the 1.2 four with the twin-air engine, and it will also appear in next year's new Panda and Uno, if the Uno comes to Europe.
However, just as the twin-air head technology is taking forever to replace the traditional valve actuation in all Fiat's petrol and Diesel engines, so it seems the company will take a long time to completely replace the small fours by the twin. But they will do this.
Which gives them pricing problems. The twin will be a better engine than the current 1.2, but if it is priced the same nobody will buy the 1.2, so Fiat will probably price it higher, but not as high as the Diesel 95, which by then will probably have had its CO2 reduced to under 100g/km and so incur no tax. Where the 1.4 fits in with all this I have no idea?
In two years time the 500 gets the lightened, strengthened chassis that the American version will get in 2011, and by then the new Panda will also have arrived, also on this (lengthened for it) chassis and with the twin engine.
The Panda is Fiat's bread and butter cheap small car and has to be priced low.
It will be interesting to see what they do. And don't forget, the Punto and Mito will get the twin cylinder engine too at some stage.