In the world of fashion, the phrase, “it’s what’s on the inside that counts”, rarely applies. But it certainly applies to Maserati’s Quattroporte GTS. The 2016 model might be the fastest, the most powerful and the most economical four-door Maserati has ever built, but trimmed with hedonistic premium Italian leather and silk woven by luxury fashion-house Ermenegildo Zegna, it’s also the best-dressed Italian on the market.

It certainly isn’t the first time a super-luxury carmaker has made a sartorial pairing with a super-luxury fashion house. As far back as 1979, there was the Cadillac Seville by Gucci. Bugatti and Hermès paired to create the Bugatti Veyron in 2008. But there’s something about the cross-pollination of Italian blue bloods that sends a tingle of appreciation down the spine, even for those who aren’t particularly sartorially inclined.

As one of the last remaining family-owned Italian-fashion empires, managed by Gildo Zegna (the Ermenegildo’s grandson), the marriage is keeping the bloodline blue. Zegna’s suits have long been numero uno for high-net-worth individuals; the mastery of Italian finishing and su misura (made-to-measure) appealing to those impeccably groomed gentlemen who are accustomed to customising everything from their lapel stitching to their luxury cars.

Putting that same level of finish into the Maserati, however, was a different ball game. The bespoke silk developed by Zegna’s technical team, which adorns the inserts on the Quattroporte’s seats, door panels, sunshades and ceiling-light fixture had to endure interminably lengthy trials to stand up to Maserati’s stringent durability standards, from being sat on umpteenth times by dummies to being scorched beneath UV rays and heat. Then there’s the amount of silk. A single men’s suit typically requires three metres of silk; Maserati’s upholstery takes 12. Initially, the collaboration was strictly limited edition (only 100 were made), but now the Zegna-edition Maserati is in production on a larger scale.

Aside from those luscious Zegna trimmings, the Quattroporte’s interiors are fitted with sporty seats, a classic Maserati analogue clock and the Maserati Touch Control screen that adjusts climate, seat heating and music. The size of the vast and beautiful cabin borders on sheer overabundance; you need to up the decibels to speak to rear passengers – who coincidentally, are enjoying the greatest amount of legroom in the standard wheelbase class.

There’s nothing shouty about the Quattroporte’s exterior, just those powerful lines, long dominating Italian nose and concave Trident grille. On the road, it gives off an unmistakable air of prestige and certainly commands respect, prowling along with the low thrumming of the 3.8-litre V8 engine. The engine, built by Ferrari in its world-leading engine-construction facility in Maranello, is Maserati’s new performance benchmark, reaching 100 kph in just 4.7 seconds, achieving a 307 kph top speed and with 200 Nm more torque and 20 percent less fuel consumption than its predecessor, the Quattroporte Sport GT S.

Partly down to the use of ultra-lightweight aluminium, used on the bulk of the body panels, the less weighty Quattroporte has delivered a 12 percent improvement in drag and an enormous 24 percent reduction in lift, reducing fuel consumption and producing a remarkable stability. And it’s also exceptionally quiet, with both the windscreen and rear window made from double-laminated acoustic glass.

All in all, it’s a cosseting drive, almost too cosseting – those finely-tuned Brembo brakes can be a touch too sensitive, proving a nuisance in stop-start traffic, as is the jarring beep of the blind-spot alert when changing lanes in heavy traffic, especially when it disrupts the cappuccino-smooth baritone of Mario Biondi (fabulous playlist, Maserati).  But when you hit the open road – and sport – it’s nothing short of exciting. A bella macchina, as lusty, hot-blooded and passionate as a pair of Italians.