Brave gamble pays off
The test for me and the challenge for Volvo was ridiculously straightforward. Could they put a 1.6-litre diesel engine in this living-room of a large executive motor and not end up with a chugging embarrassment? It might return a zillion miles to the gallon but what good would that be if they could find no-one wanting to drive it any more than a few kilometres?
There is no doubt that, on paper, it was a gamble.
I had it for a lengthy spell over the recent break and I admit I took it with real apprehension. That's because a 1.6-litre engine in a reasonably sized saloon can be found wanting.
But putting a tiny powerplant under the bonnet of a big, heavy motor like the S80 bordered on the brave, or desperate, or both. Let's not forget that in less cost-conscious days the S80 boasted large turbo petrols with severe thirsts amongst its high-octane stable.
I drove this for more than 1,100km with all sorts of loads on board and over a huge range of roads and conditions. Yes, it was fairly dirty and grimy when I'd finished. I managed not to whinge about it being slow or sluggish because, despite its understandably sedate nature, it never really made me feel I was flogging it.
However, I was disappointed at how floppy and flappy it was on the road at times. A vague steering feel didn't help, but I was aware from previous excursions in its more thirsty petrol guises of its softish suspension and shouldn't have been too surprised.
And yet that little 1.6-litre never stopped battling. Bear in mind, this big motor weighs 2,100kgs.
Indeed, I had to keep from trying to drive too slowly and too "green" because there isn't much to be gained from getting a false impression.
The tank holds 70 litres. I felt obliged to push the consumption credentials to the limit. The computer calculated that there was sufficient fuel for 70 more kilometres when I handed it back.
According to my maths, this large executive motor covered 15.5km every litre; the equivalent of 43.3mpg. The driving varied from the mad highway rush to dawdling about in the suburbs, to heavy city traffic. That sort of consumption in real-life driving is impressive.
Not as impressive, perhaps, as the 4.5 litres/100km that Volvo cite for the combined cycle of city and highway driving. Nor could I see it covering more than the 1,500km they claim is possible on one tank of juice. But it would go a fair bit of the way if a less urgent driver than I took the helm. And, no matter what, the return is a 15pc improvement compared with the two-litre diesel.
Incidentally, the DRIVe badge denotes they have made every effort to give this the best environmental credentials possible, within the confines of its component parts. To earn the badge, they tweaked the gearbox ratios for better fuel consumption. At the same time, the tyres are specially designed for low-rolling resistance and the frame itself is tailored for reduced air drag. For the first time, too, the S80 is fitted with an electric power-steering pump.
For all its "green" ambitions, this remains a likeable old car to saunter around in. You like it in the way you'd be fond of a slow-tail-wagging, easy-going sheepdog.
In terms of performance, it doesn't measure up to what buyers in this neck of the market have come to expect from their prestige-marque saloons.
But there's a lot of space, equipment and comfort within. That is where you will most likely find yourself warming to its non-technical attributes.
It embraces you with big comfortable seats fore and aft, sends you lots of reassuring signs and displays loads of instrumentation about safety devices. And there is a boot that "splits" so you can hang shopping bags and other items securely.
If you don't warm to the rather chunky looks, I don't blame you. But they do grow on you over time and you'll manage to live with them as they are part and parcel of what Volvo tried to do to make this as distinctive, if not immediately attractive, as possible.
No, the real deterrent in the S80 DRIVe is that it has the softest, least deliberate suspension system in any car across a broad sweep of the market.
This just doesn't bother to give you any sense of automotive dynamism. It is the sort of car and suspension they like in America but not nearly so much here I'm afraid.
If that doesn't bother you much, then here is an executive at your disposal for reasonable money that will cut your running costs without any loss to the class and luxury.
If you can live with its few shortcomings, then the S80 manages to make quite a case for itself on a number of fronts.