Audi R8 Spyder revealed

The world's most expensive Audi has been revealed on the eve of Europe's Frankfurt motor show.

Audi's drop-top version of its R8 supercar reaches Australia in 2010 and can be expected to race towards the $400,000 mark - closer to pricing territory traditionally associated with Lamborghinis and Ferraris.

The R8 Spyder has been revealed with the same 386kW 5.2-litre V10 as the R8 5.2 FSI coupe that debuted locally last month.

While the convertible version will be more expensive than the V10 coupe that starts at $351,000, it won't be faster.

The Spyder has a slightly lower top speed (313km/h) and is two-tenths slower in the 0-100km/h acceleration run, although with a still-highly-respectable 4.1 seconds.

Fuel consumption also increases slightly - by 0.2 litres per 100km - compared with the coupe: 14.9L/100km with the six-speed manual; 13.9L/100km with the auto.

The fabric roof contributes about a third of the Spyder's 100kg weight gain over the coupe, though Audi says the use of carbonfibre for some body parts - including the roof storage lid - helped to contain a greater increase.

Spyder owners, however, can better access the sound of the V10 engine by folding down the electro-hydraulic soft-top at the flick of a switch in 19 seconds. The roof can also be raised or lowered at speeds of up to 50km/h.

The folding roof also incorporates a heated glass window.

As with the V8 and V10 R8 coupes, the Spyder is all-wheel drive and seats two people.