What is it?

It's a special edition of the Aston's V8 Vantage coupe (or roadster); loosely inspired by Aston's GT4 racing cars.

A follow-up to the N400 of 2007, weight of the N420 has been cut by 27kg over the standard V8 Vantage, which doesn't sound like a great deal because, well, it isn't really. It has mostly come from the application of carbonfibre in place of other trim; such as lighter seats. There are carbonfibre details on the outside too and a new design of alloy wheel.

The engine remains the same 4.7-litre, 420bhp V8 as standard, while a manual or robotised-manual gearbox is offered. Most significantly is that the optional Sport Pack is fitted – that gives revised springs and dampers and thicker anti-roll bars. There's a sports exhaust, too. Oh, and optional Race Collection paintwork – different-coloured paint for the pillars/rails and grille surround, as on Aston's race cars.

What's it like?

More extreme than the regular V8 Vantage, certainly. The carbonfibre-backed seats are exceptionally supportive and, even at idle, there's a hint of greater potency from the exhaust.

The low-speed ride won't have you writing home, either. Chuck in the Alcantara finish on the steering wheel and it's a quite an engaging experience.

Changes don't run so deep as they do on, say, a Porsche 911 GT3 though. This is still a V8 Vantage, just one that's better tied to the road. So it steers with pleasing accuracy and feel, and wants to be revved with surprising vigour for a big V8. Do so and it gets along nicely, with the sports exhaust making a really belting noise when the engine's wound to the upper echelons of the rev-range.

The stiffer springing brings its rewards if you're pressing on. Turn-in is sharpened noticeably, grip is strong and the N420 improves the standard V8 Vantage's chassis feel near the limit. The car feels more planted, with less body unwanted movement as the front tyres (on a steady throttle) or the rear tyres (with trail-braking or a dose of gas) begin to reach their limits.

Because it's unchanged, the V8 engine retains its odd, slightly springy response to the pedal – as if the two are attached by a piece of elastic. It's far less noticeable on the optional Sportshift transmission fitted to our test N420. This is a single-clutch automated manual rather than a twin-clutch unit or a full auto. I quite like it, but I'd prefer a manual if the engine didn't have its slightly peculiar response, and if it didn't hang so much when you come off the throttle. The Sportshift disguises those traits well.

Should I buy one?

It's worth thinking about, certainly. If you were to spec the N420's options separately you'd end up with a bill that makes this model's £97k list price look like good value.

But the N420 isn't a full-blown Porsche 911 GT3 rival – the changes to the Porsche run deeper and truer to its motorsport roots. It feels more authentic and less superficial. While I think the best Porsches are the lightest, most stripped bare ones, conversely I think the best Astons are its more cosseting models.

What the Aston N420 is, though, is a worthily more focused and more entertaining car than the regular V8 Vantage, at an acceptable premium.