What's it like?
It looks the part, but - as with the V90 R-Design - the lowered suspension doesn’t do many favours for its ride. It’s 15mm lower, the springs have been shortened and stiffened, and it also gets passive monotube dampers which use one valve to deliver compression and rebound damping.
That translates into a ride that delivers sharp jolts and thumps over imperfections, especially around town and on B-roads. It's much better on smooth surfaces though, offering a more compliant and relaxing ride. The stiffer suspension does also offer a trade off for better driving dynamics, with tighter body control and sharper cornering, but as the improvement is only minor it’s still worth ticking the £1500 option to get adaptive dampers with rear air suspension. This removes the lowered ride height and will generally make the S90 more comfortable - which is surely one of the main reasons why you'd be considering this car anyway.
The S90 R-Design is adept at cruising over long motorway stretches, with an interior that remains quiet apart from some tyre noise over coarse surfaces, and the semi-autonomous Pilot Assist function is a great asset for removing some stress from particularly monotonous treks. But when you hit some country roads, this R-Design model ultimately doesn't deliver the same levels of engagement as its German counterparts, even if it is still enjoyable in its own right. The all-wheel drive system offers lots of grip, but the steering doesn’t offer much feel and its self-centring occasionally feels overly keen as well, especially in the weightier Dynamic mode.
Performance is impressive and it'll munch through overtakes without any problem, but it doesn't feel properly quick or agile like a BMW 5 Series 530d xDrive (which is a noticeable 1.6sec quicker from 0-62mph) does. The D5 engine does, however, have a clever PowerPulse air compressor which reduces turbo lag. This means response is good even at low revs, and power is delivered smoothly, with only the slightly sluggish eight-speed auto gearbox impeding the slickness of the acceleration.
The S90’s interior is beautifully crafted. Aside from the impeccable fit and finish there’s plenty of space for all, the boot is a good size, the 9.0in touchscreen infotainment system is incredibly intuitive and R-Design adds a crystal clear 12.3in digital instrument display.