Volvo limits its mainstream S90 models to a twin turbo 2. 0-litre four cylinder diesel engine that must be mated to an 8-speed Geartronic automatic gearbox. The base D4 variant puts out 190bhp through its front wheels. Or, alternatively, you can go for a ‘PowerPulse’ D5 derivative that boosts this unit’s output to 235bhp and only comes with AWD. Both options are acceptably frugal, the D4 managing 64. 2mpg on the combined cycle and 116g/km of CO2. If you want to do better than that, you’ll need to stretch to the top T8 Twin Engine Plug-in hybrid flagship model that mates a 320bhp turbocharged/supercharged petrol unit together with an 87bhp electric motor powered by a battery pack neatly packaged away in the transmission tunnel. When fully charged, this variant can offer up to 28 miles of all-electric driving range.

On the move, you aren’t served up anything that encourages much driving involvement -blame the rather vague steering for that - but in compensation, there’s unruffled poise and exemplary refinement. You get supple standards of ride comfort from the soft suspension too and there’s the option of rear air suspension if you want it. A standard ‘Drive Mode Settings’ driving dynamics system allows you to tailor throttle response, steering feel and auto gearshift timings to suit the way you want to drive. And if you do push on a bit, grip and traction are actually quite impressive and cornering bodyroll decently well controlled.

The design language is apparently taken from contemporary Scandinavian culture and from most angles, the resulting shape looks elegant and sophisticated. With its short overhangs, long wheel¬base and low roofline, there’s an air of confidence assurance here, yet also a look that’s uniquely Swedish, with a muscular shoulder line that’s distinctly Volvo.

Let’s take a seat up-front, where it really is very nice indeed. The first thing you’ll probably notice is the 9-inch portrait-style touchscreen on the centre console that de-clutters the cabin of buttons and gives it a classy, sophisticated air emphasised by intricate detailing and rich Scandinavian design. There’s more technology in the instrument binnacle where the normal conventional dials and read-outs have been replaced by virtual ones in an ‘Active TFT Crystal Driver’s Information Display’.

Time to take a seat in the back. Given the extra body length that the S90 enjoys over some of its rivals, you’d expect it to feel pretty spacious and, by and large it is, a clever design of front seatback further freeing up leg and kneeroom for rear seat folk.

We’ll finish by taking a look at the boot. It terms of overall size – 500-litres to be specific – this is one of the smaller trunks in the segment but it gets close enough to the capacity of the class-leaders for that not to matter too much.

In the S90, Volvo has a properly credible and very charismatic flagship saloon that will complement the discernment of the relatively few business drivers likely to choose it. Inside, there’s properly distinctive luxury, rather than merely the kind of upgrade from a smaller, cheaper model that rivals offer.

It’s all quite unexpected. From a car that may well make you rather like the unexpected.