The weight of expectation hung heavy over the RS5 when it was launched in 2010. After the RS4 saloon had come oh-so-close to beating the M3, Quattro GmbH’s first RS coupe had all the potential to finally best the BMW.
But despite a cracking naturally aspirated 4.2-litre V8, a quick-shifting dual-clutch gearbox and UK-friendly four-wheel drive, the RS5 took a step backwards, its numb steering, harsh ride and nose-led chassis dampening its appeal. What, then, of the new (and mechanically identical) RS5 Cabriolet?
So the V8 engine is still the headline act in the Audi RS5?
The 444bhp V8 – a cut-down version of the R8 supercar’s V10 – rumbles more deeply than an M3, but bellows a more cultured symphony than AMG’s barking 6.2, and despite a useful torque plateau still manages to rev out to a nutty, Ferrari-esque 8500rpm. Of course it’s louder with the roof down, but it’s actually a clearer and crisper noise with the triple-layer folding fabric hood in place. Bit boomy at idle, mind.
I bet that makes the RS5 Cabriolet pretty fast...
Surprisigly, it isn't, really. Blame the automotive equivalent of a portly Hollywood actress’s Spanx pants: 205kg of gusseting designed to stop the wobble. So although the RS5 Cabriolet exhibits little of the rigidity woes that afflicted the RS4 Cabriolet, it doesn’t punch out of hairpins or hammer quite so searingly towards the redline as the editor’s old long-term RS5 coupe.
What about the rest of the Audi RS5 Cabriolet's dynamic package?
No issues with traction, though, as the Quattro system (with one diff apportioning torque between the axles, and another taking care of shuffling duties across the rear wheels) means the RS5 just grips and goes. And while we’d prefer larger gearshift paddles, the S-tronic transmission snaps through the changes too, enabling us to drive hard and fast along our Alpine test route with little drama.
But… all the test cars came with the £2250 Sports package that bundles together bigger 20in wheels, a switchable sports exhaust, Dynamic Steering (with Comfort, Auto and Dynamic modes) and Dynamic Ride Control (ditto, governing diagonally linked dampers). No matter what mode you pick, the (secondary) ride is severe – in Audi’s own words the suspension set-up is ‘decidedly firm’ – but if you stick with Comfort to compensate, all that weight can’t be contained over sharp crests and bumps. And while the heftier Dynamic steering setting is fine for hard driving, in day-to-day ambling the RS5’s wheel weights up oddly and inconsistently.
M3 or RS5? We’d take the BMW, which is sharper at the limit and a more comfortable everyday proposition, only losing out to the Audi on all-weather traction. If you want four seats and four-wheel drive (and the 911 Carrera 4 and Bentley Conti GTC are too costly) we’d opt for the torquier and cheaper S5 Cabriolet. And if you just want a great convertible, buy a Boxster S.