26.06.2007

A beefed-up 159 prototype has been caught testing at the Nurburgring - and the Italians' GTA version is expected to switch a twin-turbo version of Holden's V6 for a Ferrari V8. By JEZ SPINKS.

Barely disguised Alfa 159 prototype provides strong clues to upcoming GTA hot-rod. Bonnet includes concealed vent and quick-release pins. Spy picture: Automedia

Alfa Romeo looks set to abandon a high-performance version of the Holden-built V6 in favour of a Ferrari V8 as the Italians' 159 GTA targets the Audi RS4 and new BMW M3.

Our spy photographers have snapped a muscular-looking 159 sedan testing at Germany's Nurburgring circuit, and the thinly disguised vents on both the front guards and the bonnet suggest this prototype is powered by a high-performance V8.

The flagship variant of the 159 was expected to be powered by a bigger-capacity, dual-turbocharged version of the Holden-built 3.2-litre V6 already included in the mid-sized Alfa's range.

It seems, however, that the Italians want to jump into the upcoming battle of V8-powered German mid-sizers that by the end of the year will include Audi's RS4, BMW's M3 and Mercedes' C63 AMG.

An Alfa insider confirmed the 159, which launched in Europe in 2005, has a platform capable of accommodating a V8 engine up to 4.5 litres in size. And Drive.com.au's source said the V8 from the Ferrari F430 has plenty of heat to disperse, which would be aided by the multiple air vents.

The supercar engine would be possible because Alfa Romeo sits under the same, large Fiat umbrella as Ferrari (as well as Maserati and Lancia). The Ferrari/Maserati joint-developed V8 has a capacity of 4.3 litres and in the Ferrari F430 produces 360kW of power and 465Nm.

The V8 would be detuned for the 159 GTA, however, whose rivals (RS4 and M3) both feature 309kW V8s. Mercedes has yet to release details of the C63 AMG that debuts at September's Frankfurt motor show.

Another clue to V8 power in our pictures are the quad exhausts on the 159 prototype, which accompany typical GTA cues such as large low-profile tyres, slightly flared wheelarches, and side skirts. The prototype also wears a rear spoiler, unlike its predecessor the 156 GTA.