Turbo Diesel



The Numbers

3.0-litre, V6 turbodiesel, 202kW, 600Nm, 8sp automatic, 0-100km/h 6.4secs, 6.2L/100km

The Topgear Verdict

A perfectly acceptable upper luxury sedan; just not a great Maserati.

2014 Maserati Quattroporte Turbo Diesel

So, what is it?

This 3.0-litre turbodiesel V6 is the third instalment in the current Maserati Quattroporte trilogy, joining the 3.0-litre, twin-turbo petrol V6 S and 3.8-litre, twin-turbo V8 GTS.

It’s the leading edge of five year new model surge that will see the famous Italian brand also launch the mid-size Ghibli sedan later this year, the game-changing Levante SUV next year, the stunning Alfieri Coupe in 2016, followed by an Alfieri Cabrio in 2017, a new GranTurismo in 2018, and GranCabrio in 2019.

Why should I care?

Aside from a price that brings cost of entry for the Quattroporte under $200K, it delivers a thumping 600Nm of torque, which isn’t far off the GTS, and opens up the big Maser luxo sedan to a fresh batch of diesel-focused premium prospects.

What's new about it?

The biggest change is hidden under the bonnet, with a 2987cc single turbo V6 sourced from Italian diesel engine specialist VM Motori, now an ‘in-house’ Fiat Powertrain subsidiary.

It’s a specifically tuned version of the A630 engine, also used in the Chrysler 300 (Lancia Thema in Italy), Jeep Grand Cherokee, and the QP’s smaller Ghibli stablemate.

That big 600Nm slug of torque arrives at just 2,000rpm, remaining flat up to 2,600rpm, and the diesel’s final drive ratio is taller (2.80:1 vs 2.93 for the petrol models) to take advantage of the low-down grunt.

And while a satisfactory shove in the back is a key part of the Maserati experience, the brand’s signature, snarling engine note is also a must.

With the aim of bringing the relatively rattly and muted sound of a diesel up to Maserati spec, the Quattroporte features an ‘Active Sound’ exhaust system, featuring two actuators near the tailpipes to enhance aural output. Press the Sport button at idle and the engine note drops to a baritone throb, with a richer sound forthcoming under hard acceleration.

That's all fine. What's it like to drive fast?

While a claimed 0-100km/h time of 6.4secs isn’t hanging around for a 1.9-tonne sedan, the diesel QP is several notches slower than the V6 petrol (5.1secs), and lags in the V8’s wake (4.7secs).

But that fat torque band still makes for rapid back-road punting, with the eight-speed transmission extracting the best of it. That said, manual shifts are a reminder of how quick current dual clutch boxes are, the auto’s flappy paddles living up to their name in this case, with a surprisingly lengthy action, and smooth, but less than snappy shifts.

Our launch drive covers around 450km of winding secondary roads, inland from Lismore on the NSW north coast. Road surfaces are a typical B-road blend of uneven coarse chip bitumen, and pock-marked, patchwork sections.

The suspension (double wishbone front, five-link rear) only just gets over the line of luxury acceptability in these conditions, delivering a bumpy ride relative to its main German competitors.

Standard rims are 19 inch, while our test example rides on 20s, shod with fat Pirelli P Zero Z-rated rubber (245/40 f – 285/35 r). But even a plus one inch wheel step up isn’t enough to account for the bumpiness.

Mid-corner irregularities upset the car’s balance, and switching the semi-active system from Comfort to Sport mode only accentuates the issue.

Eschewing the current trend towards weight saving electric steering, the Quattroporte features servo-powered, hydraulically assisted steering, with the amount of assistance reduced to deliver more feedback.

No surprise then that steering response is crisp and accurate on turn-in, with good road feel. But the feedback bit is where things take a (ahem) turn for the worse, with too much jittery reaction coming up through the wheel.

Then there’s the engine note, or lack of it. Despite active augmentation and amplification, the engine sound and exhaust note are less than inspiring, and very un-Maserati. At 70percent throttle and above there’s a distinctive, if relatively muted note. But at anything less than that, and let’s face it, that’s most of the time, the diesel is quiet and distinctly non-growly.

Brake rotors are the same size as the two petrol turbos, but the diesel’s, while ventilated, are conventional cast, rather than cross-drilled dual cast, with four rather than six piston calipers on the front. No complaints in the stopping department though.

And driving from home to the office in the city?

At around-town cruising speeds, on slightly more forgiving urban roads, the QP diesel is a peaceful place to be.

The front seats are comfortable, and a generous 3,171mm wheelbase means there’s plenty of legroom, not to mention head and shoulder room in the rear. The boot is generous, too.

Full leather trim is super luxurious, and the dash design is sparse and refined. A TFT colour display and control screen dominates the centre console, although the dark wood veneer trim on the dash does its best to look and feel artificial.

The multi-speaker audio system is appropriately awesome, and the optical fibre interior lighting adds an air of after dark sophistication.

Is there anything bad about it?

The big three are the firm suspension tune, steering feedback, and lack of engine/exhaust excitement.

How much would I have to pay for one? And is it worth the coin?

At $198,800 the QP TD is a hefty $121K less than the flagship twin-turbo V8 version ($319,800), yet it’s still loaded with the copious amounts of standard equipment you’d expect of a car in this part of the market. So yes, the value equation adds up.

Maserati expects the diesel to account for 10 per cent of Quattroporte sales, and given the sticker price, it won’t be bought for its fuel economy, although that’s impressive. The belief is the main considerations will be range (an easy 1,000km at constant freeway speeds), and fuel availability (compared with 98RON unleaded).

Would you take this or the Audi A8 TDI quattro?

The Maserati is in exactly the same price ballpark as the big Audi, as well as BMW’s 730d, and the Mercedes-Benz S350 BlueTec. We’d take the Audi, if only because the Maserati doesn’t do anything better than it, the signature Maserati snarl is missing in action, and the big Bavarian is faster.

Driven: June 30, 2014