UNTIL THE big boy RS5 is unleashed on unsuspecting M4s and C63s later this year, the new Audi S5 serves as their hardest-hitting mid-size coupe.

With two doors, four seats, a longitudinal, permanent quattro all-wheel drive and a torquey turbocharged V6, it’s a car made to a time-honoured mechanical template for Audi.

Although it’s powered by six cylinders rather than five, this is the closest thing to a classic 1980s Ur Quattro that the firm currently makes. And that might count for something given that people who are in the market for a fast coupe like this are probably just the right age to fondly remember the 1980s.

2017 Audi S5 rear

The figures aren’t eye-popping, particularly alongside rivals like the bigger-hitting Mercedes-AMG C43 Coupe, yet the S5’s 260kW/500Nm is still nothing to complain about. Nor the potential for 0-100km/h in less than five seconds.

The S5 also gets its own suspension tune, riding lower than even sports-sprung versions of the standard A5. But here, Audi’s trick is to mix in greater comfort and civility than you might get in a more powerful RS.

2017 Audi S5 interior

The motor is a worthwhile improvement over what it replaces but doesn’t always combine brilliantly with the eight-speed gearbox. Overall, we suspect petrolheads will still narrowly prefer either AMG’s new 3.0-litre turbo V6 or BMW’s longer-serving 3.0-litre straight six.

The S5’s chassis, meanwhile, seems to do 90 per cent of what most owners will desire, very proficiently – but it isn’t a natural entertainer. Even with Audi’s optional sport rear differential, our test car wasn’t particularly poised or engaging when cornering, although it was always grippy, precise and sure-footed.

2017 Audi S5 side

Audi probably needs to do more with its S-branded cars to successfully counter the threat from AMG’s more engaging 43-badged line-up. If it can, this performance niche’s newly competitive forces might yet bring us a worthy successor to the original 1980s Quattro – but they haven’t done so for now.

3.5 OUT OF 5 STARS

Like Traction; grunty turbo V6; great interior

Dislike Could and should be more involving; tough rivals

Specs Engine: 2995cc V6, DOHC, 24v, turbo Power: 260kW @ 5400-6400rpm Torque: 500Nm @ 1370-4500rpm Weight: 1615kg 0-100km/h: 4.7sec (claimed) Price: $120,000 (est)