Super Siblings – Audi S4 and S5

Generally speaking, we don’t like to combine road test write-ups like this, but we figured since these cars are so similar to each other, and each had the same trim level and options (more or less), we could safely combine them, to save you, our valued reader, from unneeded repetition.

Both S4 and S5 models were updated for 2013 with new bits of technology, some of which were inherited from big sibling A8, by way of the new A6 and A7 cousins. The industry leading MMI system received updated system menus for better usability, Audi Connect (a cellular data based internet connection, which also turns the car into a mobile hotspot for up to 8 devices), Google Earth with map overlay(thanks to Audi Connect), and navigation plus with voice control. We spent more time playing with the voice commands than we’d care to admit, and we found that it was much easier to use than even the brilliant MMI hand controls, especially while driving. No longer useful just for dialing the phone, Audi’s voice control can be used to enter destination address information, or search for on line destinations via Google. You can even change the radio station or media input device using the voice controls.

The updated B8 cars also receive Audi’s new electromechanical power steering, which replaces the hydraulic system entirely. Note that this is not “steer by wire”, there is still a direct mechanical connection between the steering whelel and the rack and pinion, this new system is there to provide steering assist. Because there is no hydraulic pump being turned by the engine, there is less parasitic drag on the engine, and more of the engine’s power is used to propel the car instead of turning a hydraulic pump. And, since electric motors can stop and start instantly, the system is only called for when needed, reducing draw on the electrical system. Steering feel remains very good, essentially identical to the previous hydraulic system. At low speeds, the effort is light. As speed increases, the steering weight does too, and we feel, it’s a bit too much at times. With Drive Select, the amount of increase can be selected, which is good. Call us old fashioned, but overly high steering effort isn’t sporty, it’s just heavier effort. Also note, the dynamic steering in the B8 is only related to effort, as this platform doesn’t have the variable ratio steering rack of the larger models.

Next on the list of changes is perhaps the most controversial change of all to enthusiasts, and that is the S5’s engine. When the S5 was introduced way back in 2007, it was the first model of the new B8 platform, and it had under its sexy hood an equally sexy 4.2 liter FSI V8 engine. The engine was shared by the RS4, though the S5 variant didn’t rev quite as high, or make as much power. Nevertheless, the V8 powered S5 was hugely successful, no surprise given the incredibly sexy body, combined with the V8 power, and throbbing exhaust note.

Fast forward a few years and things like fuel economy and CO2 began to weigh heavily on the auto industry. This of meant smaller, more frugal and cleaner engines would be needed. During this time, Audi released the redesigned the A4 and S4, which mirrored the new architecture and design of the smash hit A5/S5. When the B8 S4 was introduced, it came not with the throbbing V8 engine of the previous 2 generations of S4, but instead, a 3 liter supercharged V6 engine. It should also be noted that the S5 Cabriolet only came with the 3.0TFSI engine, and we have enjoyed that combination very much, so it made sense to us that we’d enjoy the 3.0TFSI in the S5 coupe. And we did.

For fans of the biturbo B5 S4 models, and not the recent V8 powered cars, this return to forced induction was seen as a welcome change, since with forced induction comes the potential for relatively easy tuning, with significant power increases. For that reason, the 3.0TFSI engine was not seen as a negative with the B8 S4 enthusiast community, but as a plus.

With the change from the V8 in the S5 however, we’ve been hearing current and future S5 owners lamenting the loss of the glorious V8 rumble and the V8’s slightly more vigorous top end pull. Even we did find that the V6 lacks a certain sonorous quality that only a V8 can produce. It’s not that the V6 sounds bad, but it is just different than a V8. Quite honestly, we like the V6 sound. It is a bit more “racy” sounding to our ears. Truth be told, we also wish there was just a tiny bit more of the soundtrack from the supercharger. You can hear hints at Luckily though, thanks to the optional Drive Select system, the driver can call for a bit more engine sound, and to our ears, it sounds very good, especially at full chat.

There is no performance penalty resulting from this engine change either. The fact of the matter is, the 3.0TFSI, with only 20hp less than the 4.2 FSI, but with less weight and better low end power, this new version of the S5 has the same 0-60 acceleration time – 4.9 seconds. And, Audi also claims that the S tronic and 6 speed manual both run to 60 in the identical time. Incidentally, the S4 also runs to 60 in 4.9 seconds. Both siblings are electronically limited to 155, and neither has any difficulty reaching that speed.

It is also important to note that North America will be the only place where the 6 speed manual transmission will be offered in these Super Siblings. The rest of the world will have to “make do” with the fabulous – if somewhat less driver involving- 7 speed S Tronic dual clutch transmission. We sit solidly on the fence with regards to this transmission choice. The 7 speed is exceedingly good, and also makes use of the new lighter weight and more rear-biased Crown Gear center differential (the 6 speed manual uses the older tried and true Torsen differential). We do love a good manual though, and the Audi 6 speed is a good manual. Clutch action is light, and the shifter itself is fun to row. Genuine heel-toe downshifts are possible, and the barky sounds from the exhaust in Dynamic mode make reward perfectly timed shifts.

Both of the Super Siblings we tested were fitted with Audi’s Sport Rear Differential. This is quite possibly one of the finest and most clever pieces of drivetrain technology fitted to any modern Audi. What it does, quite simply, is transform the way the car goes around corners. Even though our 6MT cars had the “old fashioned” Torsen diff (with less rear bias than the Crown Gear), thanks to the Sport Differential, both cars had a decidedly rear drive feel. The cornering behavior is somewhat difficult to describe, but in a nutshell, under full power coming out of a turn, instead of the front pushing wide, the car instead feels as if the rear axle is actually pushing the nose inward. This is accomplished by the rear differential over-driving the outside wheel via hydraulically activated clutches and other magic residing within the rear differential housing. This effect is present both under acceleration, and deceleration, which aids high speed stability greatly. This also results in zero understeer, neutral cornering, and a wonderfully fun, safe drive. We also found that on slippery surfaces, the Sport Differential allows for ridiculous slip angles while maintaining complete control over the situation, and makes the driver feel like a drift king as it works its magic.

Even though both cars share the same basic pieces beneath the sculpted bodywork; the S5 has a shorter wheelbase, and a slightly wider track than the S4. As a result, the S5 is incredibly stable, yet changes direction with ease. The longer and slightly narrower S4 feels like it is glued to the road as well, but it has a slightly more casual nature in quick turns. The S4 is arguably more comfortable on longer drives, though neither is uncomfortable at any time.

All of the technical bits aside, we genuinely love the Super Siblings. Why? They don’t do anything wrong. They are fitted with quite possibly the most comfortable “sport” seats we’ve ever sampled. The suspension tuning somehow manages to resist body roll for relatively flat cornering, while allowing a sporty yet supple ride. And the chunky flat bottomed steering wheel is by far the best steering wheel ever fitted to a production car.

Yep, we love these Super Siblings. To us, they are the perfect blend of sport and comfort, sexy and practical. And they are offered with a choice of doors, depending on your needs. Perfect!