Used test: Audi R8 Spyder vs Porsche 911 Cabriolet

Winter may not seem the right time to test two supercar convertibles, but today’s soft-tops are so well built that they offer year-round comfort and warmth, roof up or down. And when you’re talking high-performance machines such as the Audi R8 Spyder and Porsche 911 Cabriolet, they can be both cosy and exhilarating at the same time. We put used versions of both to the test to see which offers the best balance.

The 911 has delivered usable performance for more than half a century. Our car’s rear-mounted 3.8-litre flat-six pumps out 394bhp. Meanwhile, Audi’s contender may not have the heritage, but with its 424bhp 4.2 V8 it certainly channels the spirit of sister brand Lamborghini.

The R8 Spyder’s centrally mounted powerplant gives it terrific balance, and four-wheel drive helps cope with the extra power. It is the heavier car here, though, which means it’s not quite as fast off the line as the 911. Both cars have their own distinctive soundtrack: the Porsche’s utterly glorious signature flat-six sounds evocative, while the Audi’s V8 roar is equally thrilling. Lowering the cars’ tops only enhances the experience for the driver.

Porsche’s legendary handling prowess sees the 911 scything along B-roads with spot-on steering and impeccable control. The connection is visceral. Yet astonishingly the Audi is even more impressive. It beats the Porsche at its own game, with superlative hydraulic steering and cornering ability that sees this big, wide machine remain flat and utterly planted. Only its slightly clunky six-speed manual box slows things down a tad; it’s licked by the 911’s slick ’n quick seven-speed auto.

Take things a little more slowly, and the Porsche proves itself easy to drive, smoother and easier on the instant response. The Audi’s more urgent and immediate feel makes smooth, steady driving a little more difficult. Its lower gearing also means it’s turning over at 3000rpm at 70mph, whereas the 911 shows only 2150rpm. Sophisticated suspension set-ups mean both these supercars exhibit good ride quality, with the Audi absorbing poor surfaces a little better.

Cabin comparisons normally favour Audi, but here – and despite the R8 having the newer design – surprisingly its interior looks more dated against the Porsche’s totally contemporary and very luxurious offering. The 911 is also more spacious, with extra headroom and two small rear seats, while roof down it offers more wind protection.

When buying used, cost is a big factor, and here that previous owners would have taken around a £30,000 hit on the Porsche and £40,000 on the Audi. That makes the Audi slightly cheaper now – but you might also want to know it returns only 19.6mpg against the Porsche’s 29.1mpg. Does the fact the R8 might well make classic status in a few years time as Audi’s first supercar ease the pain? Oh, and servicing isn’t cheap for either car, while road tax is £520 a year for the 911 and £535 for the R8.

While the everyday usability of this kind of supercar is better than ever, their use as a regular commuter is unlikely – especially as piling on the miles would adversely affect their depreciation rate. But as a weekend warrior and holiday toy, either is utterly fabulous. The wondrous Audi R8 Spyder narrowly takes the win thanks to its more fun and rewarding drive. It really is rather special – and its imminent rise in value is a bonus. It eclipses by a small margin the utterly beguiling 911 Cabriolet – although the Porsche is the one to buy if you do intend to drive it regularly.

Audi R8 Spyder 4.2 V8

Porsche 911 Cabriolet 3.8 S

Price today is based on a 2012 car with average mileage and full service history, correct at time of writing