When I, I was so thrilled by the feeling of performance and the smooth-shifting six speed that I powered off the line from two consecutive traffic lights, and got a fortunately brief talking-to from a local police officer who happened to observe my antics. The 2015 Audi S5 may be down two cylinders from that earlier example, but it is every bit as exhilarating to drive.
The Audi S5's natural rival is the BMW 435i, or more specifically, the 435i xDrive, but I'm not going to make the case for one over the other. The S5 is more powerful and the 4-series costs a little less. Drive each and see which one you like the best.
The S5 is a coupe, with two doors and two cramped rear seats, the sport version of the Audi A5. Although beauty is in the eye of the beholder, I think many would agree that the S5 is just a gorgeous bit of automotive design. It's the kind of car that will make you happy every time you see it.
Where the earlier generation S5 had a V-8, this generation makes use of a 3-liter V-6, but makes up for the power deficit with a supercharger, a somewhat unique bit of forced induction technology among currently available vehicles. The S5 also comes standard with Audi's all-wheel-drive system, Quattro, a help both in sport driving and on slippery roads.
In the US, the S5 starts at $52,500, but there are some crucial performance upgrades you will need, and excellent tech options you will want. The example I drove priced out at $58,775. Audi doesn't change the driveline for other markets, so British and Australian buyers will also get the supercharged V-6 and Quattro, at a base price of £42,675 in the UK and AU$119,900 in Australia.
The S5's supercharger comes from supplier Eaton, and uses two rotors with thick vanes to compress air at 11.6 psi, pumping it into the fuel system to get the 3-liter V-6 engine's output up to 333 horsepower and 325 pound-feet of torque. Unlike how a turbocharger is driven by an engine's exhaust, the supercharger gets turned by the engine's piston action, meaning it compresses air as soon as the engine starts turning. The result was immediate, gratifying acceleration, which I indulged in sparsely populated rural areas to avoid another stern warning.
Off the line with the S5, it was a quick slip to 6,000 rpm on the tachometer, then clutch in and shift to second for another big power boost, the engine note an aggressive growl heard even through the premium quality cabin sound deadening.
The six-speed shifts with wonderful accuracy and smoothness in the S5, such that it was comfortable driving in stop-and-go traffic and even making hill starts on steep streets, the latter helped by a useful hill-start feature in the car. Audi offers its seven-speed dual-clutch automated manual, or S-tronic, transmission as an option, and I wouldn't fault anyone for taking it. In other Audis I have reviewed, that transmission makes quick, satisfying shifts at the flick of a steering-wheel-mounted paddle, and it will likely improve your lap times if that's your aim.
For more responsive performance, the S5 includes DriveSelect, a feature that let me switch between Dynamic and Comfort modes. These modes affect the electric power-steering program, throttle response and exhaust sound, making them tighter and more aggressive for Dynamic. Switching between them, I didn't find a huge difference -- the car didn't get too sloppy in Comfort mode, nor was it at all difficult to rein in while set to Dynamic. Audi tends to program its steering for lightness, making the wheel easy to turn, and that was in evidence with the S5. I personally prefer a little more heft on the wheel, but with the S5's program I could quickly make steering adjustments in the turns without the car fighting me.
As this S5 also had Audi's Sport Differential option, Dynamic mode changed its program. The Sport Differential complements the Quattro system. Where Quattro defaults to a 40:60 front-rear torque split, shifting power between the front and rear wheels depending on traction, the Sport Differential dynamically splits torque between the right- and left-rear wheels. In a turn, it overdrives the outside rear wheel, and the result is pure brilliance. When I aimed the S5 through a set of hairpin turns, the differential made the back of the car come around more sharply, giving me a bit of predictable oversteer. You can get a similar effect in a rear-wheel-drive car, throwing its back-end out in a turn, but it felt so much more controlled in the S5.
An option missing on this S5 was the adaptive suspension, a steal at only $1,000. Also affected by DriveSelect, it would have made for a softer ride in Comfort and a stiffer ride in Dynamic. The S5's fixed suspension is well-engineered and didn't let me down in the turns, but it had to strike a compromise between pliable ride quality and holding the body flat during fast cornering.
Dropping the V-8 in favor of the supercharged six-cylinder engine was an efficiency move, similar to what many automakers are doing. The power output from the six-cylinder is roughly equivalent to that of the eight, but fuel economy comes in at 17 mpg city and 26 mpg highway, an average of 4 mpg better than the previous generation. On a run that involved significant freeway time, sport driving on backroads, and a little bit of city traffic, I came in at 20.4 mpg.