The Volvo S60 is, officially, no longer 'naughty' - the product of a bizarre, erstwhile marketing campaign - but it certainly has a swagger in its step.The compact exec has its work cut out in a sector that includes big-hitters such as the BMW 3 Series, Audi A4 and Mercedes C-Class but, as part of an evolution of Volvo's design language the S60's lines are pleasing to the eye inside and out.It's recognisably part of the 'businessman on business' set that traipse up and down the UK's Ms (1, 3, 4, 5, 6, 25 and 62 in the main) but there's something more to it. There's an kammback-like rear tailgate that's almost vertical for starters - not as pronounced as the previous S60 but still there - and its wedgy proportions are certainly different in the sector.It's pretty low to the ground too, but all those fine lines aren't just for show - the new S60 boasts a slippery drag coefficient of 0.28, which is about as low as volume cars get.Get inside and there are more eye-pleasing details. The floating centre stack that's now a feature on all Volvo models was first spotted on the S60 concept a couple of years back. It looked radical then but it almost makes sense now - I get the impression it's a love-it-or-hate-it feature however.There are few other features that stand out so clearly, but modern Volvo interiors have a way of looking and feeling good without making a big deal of it. Buttons and dials all feel sturdy; materials and panels feel nice and look good. All of the buttons are in places you expect them, although the rotary knob that controls satnav inputs is, perhaps, not the easiest way to input instructions.The interior on my test car was kitted out in two-tone leather-faced off-black and beachwood. I thought it looked extremely cool, like a tan leather jacket on a 70s detective. Smart but stylish.I do like the chairs on modern Volvos too - although my decrepit back always appreciates a lumbar support control. Spending a good ten hours in the S60 left me feeling fresh and flexible though.Up front there's good space for driver and front passenger - though the floating console does intrude a little if you want to stretch your legs and there's no footrest for your left leg - but rear passenger room does feel compromised by the curvy profile. My passengers thought the rear rather stingy on room.The boot is a rather awkward shape and - at 339 litres - not large either. Buy a large family car with its own boot and you might add another 150 litres to that figure. There are plenty of storage spaces around the cabin however, even if they don't quite compensate for the snug boot. S60 specification and gadgetry As is common these days, the difference between specification levels can amount to a stiff premium, so a spot of work with a pencil and calculator is always wise when speccing up a potential new car.My model was a S60 D3 SE Lux, which normally retails at £28,445 and includes such delights as folding, heated door mirrors; rain-sensing windscreen; an CD-radio system with Bluetooth, aux socket and USB; driver's memory seat; a raft of airbags; plenty of passive and active safety kit; Blind Spot Information System (BLIS); City Safety and climate control as standard.Chuck in Driver Support Pack, Premium Pack, Security Pack, Winter Pack, metallic paint and heated front seats and the cost leaps to £33,200. That's a lot of cash but you do get virtually every gadget and toy going.This is where new Volvos really steal a march on the opposition. They are gadget-heavy machines that integrate new technology into the driving experience as seamlessly as possible and marry the whole package up into a comfortable, good-looking and hi-tech experience.City Safety will warn you if there's another vehicle or passenger the car determines to be a potential crash hazard at low speeds. On a city road a young mother with a pushchair threatened to emerge from between two parked cars; I'd seen her but the audio and visual warnings would have been most welcome had I not.Lane Departure warnings activate if the car does not see an obvious reason for you breaking the white lines while driving; while adaptive cruise control latches onto the car in front and adapts your speed to theirs; BLIS detects drivers approaching in that area covered by neither eyesight nor rear-view mirrors; parking aids add simple audio guidance to tight parking.Taken by themselves they are clever gadgets; put them together and you have the framework for a car that can drive itself, something Volvo is clearly keen to demonstrate the viability of.Here and now they combine to make the S60 an incredibly relaxing drive. Set up the various programmes and you can cruise on the motorway and only add steering inputs for hours at a time.The motorway is, especially in D3 format, a place the S60 feels most at home. While it has a chassis set up to be 'sporty' and 'dynamic' - and lots of other words that fall out of press releases like leaves from a tree - the S60 feels, above all, comfortable.It will tolerate some enthusiastic driving and never felt jittery or wallowy but there are better cars on the market for slinging around B roads - the S60 just feels like it's been set up to be a nice car to drive, rather than a sporty car, despite torque vectoring that aids cornering. It will eat up unsettled surfaces and proves serene on the motorway, despite some road and wind noise intrusion. Approach it thusly and you won't be disappointed. D3 engine &nsbp;The D3 engine has the hint of a pleasing rasp to it when pushed, but cruising in sixth gear it's exceptionally quiet. Hit a sweet spot and - with the help of auto stop-start and some long gearing - you can see the predicted range on the S60's trip computer go way above 900 miles.I managed 45mpg with the six-speed manual box with a combination of city driving, twisty B roads and a few hours on the motorway - some way short of the official combined figure of 57.6mpg but reasonable given the kind of driving I was putting it through.Given more relaxed driving conditions a more impressive figure is surely possible - particularly with more use of the cruise control on the motorway. A notional 50mpg+ combined fuel economy, along with CO2 emissions of 129g/km making for a road tax band D - exempt in the first year and £80 thereafter. BIK is 18 per cent - meaning £1,029 for 20 per cent tax-payers and £2,058 for 40 per centers.Power comes from Volvo's 2.0-litre five-cylinder diesel engine putting out 160bhp and 295lb-ft (400Nm) of torque. That's good for a sprint time of 8.7 seconds and top speed of 137mph.Torque is rather peaky - arriving in a surge at around 1300rpm and vanishing just as abruptly at 2800rpm - meaning overtaking is relatively easy at motorway and B road speeds but grunt can be hard to locate when pulling away or accelerating at higher revs. Some good old-fashioned stick work is required as a result - an autobox may make sense but you'll sacrifice some fuel economy and other running costs (road tax is £165 higher) and performance - as well as shelling out around £1,500 more for the automatic transmission.There's plenty of towing ability however, with a maximum braked towing weight of 1600kg meaning the D3 is among the S60 range's meatiest pullers.The D3 is a funny engine. The moniker, for one seems misleading: it has five cylinders and an overall displacement of two litres - where does the 'three' come into it? Clearly there's a rationale behind Volvo's alphanumericals, but they can't fail to be confusing to customers.For what it's worth the D3 is smooth and refined and, on paper, offers some very impressive running costs. Yet step up the D5 - a larger 2.4-litre version of the same engine - and you can have more power, more torque, more flexibility, faster acceleration, a higher top speed, improved fuel economy and lower carbon emissions.Road tax is the same and your trips to the pump will work out cheaper with the larger D5 through a peculiar quirk of Volvo's engine tweakery. The D5 will cost more money to buy, but business users or those buying on finance will hardly notice the difference.Despite being rather quieter and more refined, the D3 is in something of a no-man's land, sandwiched between the larger D5 and the ultra-frugal DRIVe model that offer lower fuel consumption, CO2 emissions and performance.It may leave some head-scratching in terms of which model to choose, but the D3 is an able performer in its own right and may prove easiet to live with. Do your maths, work out your priorities and test drive all three if you've settled for a diesel S60 (which nearly 90 per cent of S60 buyers do). If you're feeling fruity go for the utterly bonkers yet loveable T6 petrol engine - it's an absolute hoot.The T6 should, perhaps, be viewed as the unhinged cousin to the rest of the S60 range, however; the only car in the range that could get away with calling itself naughty.The S60 at its heart is a range that offers - above all - comfort and style, and offers them in buckets. Find an engine to suit you and the S60 becomes very nice, not naughty, indeed. Volvo S60 Milestones Volvo S60 D3 SE LuxPrice: £28,445 (£33,200 with options)Engine: 2.0-litre five-cylinder turbodiesel via six-speed manual boxPerformance: 163bhp, 400Nm (295lb-ft); combined fuel economy 57.6; CO2 - 129 (VED band D)Boot capacity: 339 litresTowing capability: 1600kg unbrakedPros: Good looks, high quality interior, well-balanced D3 engine, potentially low running costs, comfortCons: Small boot, rear passenger space cramped, handling not the most dynamic in sector