The initial impression is one of thoroughness. Its design may lean heavily on that of its predecessor but the subtle styling nuances and overall precision in the fit of its frameless doors is quite superb.
The attention to detail continues in the cabin, which carries a combination of materials and controls of a much higher perceived quality than those found in its BMW or Mercedes-AMG rivals. The front sports seats offer plenty of lateral support and a reasonable amount of adjustment and all-round visibility is sound, although the C-pillars sometimes prove an impediment during quick over-shoulder glances.
The dashboard and wide centre console house the latest evolution of Audi’s MMI infotainment system. A 7.0in centre-mounted display is standard, although the 12.3in Virtual Cockpit and head-up display unit of our test car remain options.
Well-shaped rear door apertures provide good if not excellent access. Adults can be accommodated in the back, although the heavy curvature of the roof means head room is a little limited. For the record, Audi claims an added 24mm of knee room and 11mm of extra shoulder room. An electronically operated tailgate is standard, while the boot has a 15-litre increase in capacity over its predecessor, at 480 litres. With 40/20/40 split rear seats folded, this can be extended to 1300 litres.
Positive impressions continue as you get under way. With greater torque arriving earlier in the rev range, the S5 Sportback proves highly flexible and responsive around town. In lower gears out on the open road it pulls with real earnest when its reserves are unleashed with a heavy nudge of the throttle, propelling the new five-door liftback along with great authority.
An alluring soundtrack accompanies this flexibility and urgency. On light throttle loads there's a raspy exhaust note that grows in volume and intensity, ultimately becoming quite menacing in Dynamic mode on the approach to the 7500rpm redline.
The eight-speed automatic gearbox offers greater smoothness than the old seven-speed S tronic dual-clutch automatic, especially on downshifts, although it did baulk occasionally when hurried with rapid-fire manual shifts at higher revs.
Audi claims a 0-62mph time of 4.7sec, which is 0.4sec quicker than the old S5 Sportback. Despite the extra performance, fuel consumption is improved by 2.0mpg at 38.7mpg, while CO2 emissions are rated at 166g/km.
The handling is well resolved, although enthusiasts may bemoan a lack of real involvement over challenging roads. With excellent body control and improved balance you can carry impressive speed through corners. Overall there is greater fluidity and sense of willingness to the new S5 Sportback compared to its predecessor, but it fails to offer the outright verve of the 440i GranCoupé or the feedback of the C43 Coupé.
Grip is always in abundance thanks to the fast-acting qualities of the quattro four-wheel drive system. Yet while the steering offers improved response upon turn-in, it lacks the communication required to make the S5 Sportback a truly great-handling car rather than merely a highly accomplished one.
Crucially, the ride is much improved, with more supple low-speed qualities and improved authority on broken roads in Comfort mode. Sport mode stiffens things, although the overall composure remains. It is a big improvement, adding a degree of comfort that was lacking before. The suspension also isolates road noise better than it did.