Are you the sort of person who chooses a new car with your heart or your head? If you're the former, I'm not going to waste any more of your time here. Best be on your way, making sure you steer well clear of any potentially costly traps such as Alfa Romeo dealers as you go about your business. If, on the other hand, you prefer a car that makes all sorts of financial sense without skimping on the finer things, chances are you're going to quite like Volvo's latest take on the S80, and especially so when it's fitted with the D5 diesel engine.

Volvo offer two diesels for the latest S80. There's a 2.4-litre model that serves up 163bhp and 340Nm of torque or there's the engine we're interested in here, the D5, which is good for 185bhp and 400Nm of torque. If you're at all up to date with current diesel engine development, you'll know that the 2.4-litre engine could be categorised as 'Barely Adequate' and the D5 as 'Getting Warm'. Neither of these five-cylinder engines are going to pin you to your seat in the way that some BMW, Audi or Mercedes diesels will but then, the Volvo doesn't command those sorts of prices.

In fact, the Swedish company have played their cards rather smartly in slotting the S80 in considerably cheaper than an equivalent 5 Series, A6 or E-Class. As a point of reference, you'd need over £32,000 to buy a Mercedes E-Class with a broadly similar power output which is around £6,000 more than the Volvo and will come with a far meaner roster of standard equipment. If we're realistic, specifying the Mercedes to match the Volvo will add another £2,500 onto that differential. Given the fact that the S80 is the newer, more technically advanced product, it's not hard to see why Volvo are so bullish.

"The S80 D5 must walk a tightrope between the mainstream and the true premium brands. That doesn't give it a whole lot of scope for expression"

The engine isn't merely an old lump in new clothes either. It has recently been revised with an electronically-controlled turbocharger, refined multi-throttle injection technology and an optimised engine management system to provide higher performance, improved flexibility and a reduction in emissions. Volvo are acutely aware that the S80 D5 will sell in big numbers to corporate buyers who could plump for a 5 Series but would like something that not every other suit in the car park is stepping out of. Therefore, the S80 needs to be competitive on carbon dioxide emissions in order to reduce the benefit-in-kind taxation. Buyers get the choice of front or all wheel drive with the latter coming at a £1,200 premium.

Most will see this vehicle as a facelift instead of the all-new car it actually is. They'll spot the reassuringly familiar proportions, the solid, dependable Volvo design cues and the emphasis on safety and assume that all is pretty much as before. No amount of free beer or consumer durables is going to change this perception. Their loss. For those who are either easily attracted by my cheap attention seeking or who are a little more curious about this latest big Volvo, there's plenty worth looking at.

Let's start with that styling. It's only when you get the old S80 next to the latest car that you'll see quite how far it has evolved. Yes, many of the primary design cues are still much the same. The car retains the distinctive shoulders that run all the way back to the tail lights that look like a piece of ornate marquetry. The roofline is still arched in an almost coupe-like manner and there's still a rather bluff grille up front. Where the biggest changes have been made is in the vehicle's stance and its fine detailing. Compared to the latest model, the old car looks notably less athletic. It seems to ride higher and the front and rear overhangs are longer. Break out the tape measure and you'll realise that the current S80 is exactly the same length as its predecessor, significantly longer in the wheelbase, and a smidgeon wider and higher.

The interior pursues a different set of design goals than many of the S80's direct rivals. It's refreshing that a premium manufacturer has the nous to go its own way in terms of design and the S80's 'Scandinavian Luxury' take differs from the increasingly prevalent Teutonic themes offered by the majority of the other premium brands. Volvo claim their 'design language' radiates a simpler, more stylish and modern feel by combining aesthetics and technology in a more inviting and intelligent way. The interior design offers a blend of no-nonsense Scandinavian style with a slim 'floating' centre stack, quality materials for upholsteries and a choice of inlays and colour schemes that blend smoothly together. As ever, Volvo is highly committed to providing safety leadership in its class.

Safety technology for the S80 includes a unique Personal Car Communicator (PCC) and new active safety systems - Collision Warning and Brake Support - with Adaptive Cruise Control (ACC), active Bi-Xenon headlights and a patented body structure developed at the Volvo Safety Centre. The S80 includes an optional key fob offering 'keyless drive' and incorporating a world first innovation - the Personal Car Communicator (PCC). This features intelligent technology to remotely check if the car is locked or not, then alert you if the alarm has been activated, and a heartbeat sensor which warns if there is anyone in the car.

Another interesting technology is the Collision Warning system which alerts the driver, via a 'heads-up' warning display on the windscreen and an audible buzzer, if the gap to the car in front closes so fast that a collision is likely. Meanwhile, the Brake Support system boosts the braking force to ensure braking is as effective as possible. The active Bi-Xenon headlights turn the beam of the headlights in the direction the steering wheel is being turned, allowing better visibility deeper into corners at night and also helping to highlight the immediate verge where a pedestrian, cyclist or parked vehicle could be obscured.

The S80's low key introduction masks the fact that a whole host of changes have been made. The D5 engine remains probably the most appealing powerplant in the entire line up but buyers in this class are developing a taste for 200bhp+ diesel engines. If you're a pragmatist, you may well surmise that 185bhp is just about enough.