While it currently competes with BMW and Mercedes-Benz for supremacy on the premium market, Audi was nowhere near as fancy as a brand some three decades ago. But the Ingolstadt-based firm evolved quite dramatically in the 1990s and 2000s, and it's now selling a handful of highly appreciated premium vehicles, including the A4, A6, A8, and Q7. However, while Audi joined several new niches in recent years, it still doesn't have a competitor for the relatively new Mercedes-Benz S-Class Coupe. But this will change soon, as Audi is already working on the A9, a two-door version of the new A8 and its largest, most luxurious coupe yet. Alongisde the A9, Audi is also rumored to have an RS9 model in the works. The latter will compete against the Mercedes-AMG S63 and the recently confirmed BMW M8.

There's no official word as to when the A9 will arrive, but it will be heavily based on the Prologue Concept that Audi launched back in 2014. The show car has already inspired the design of the new A8, but its coupe configuration might make it into production with very few changes. As with all RS-badged models, the RS9 will be a beefed-up version of the A9, with revised aerodynamics, bespoke features inside, and a more powerful engine under the hood. The RS9 will enable Audi to compete in the still fresh performance, luxury coupe market that will soon include both Mercedes-Benz and BMW, Ingolstadt's most important rivals. Let's find out what it may bring to the table.

Continue reading to learn more about the upcoming Audi RS9.

Exterior

With the latest-generation A8 in full view and on its way to showrooms, we have a good base for the A9's design. Like its competitors, Audi will be looking to roll out a coupe that's recognizable as an Audi as well as a sibling of its range-topping vehicle. So it's safe tu assume that the front fascia will be almost identical to the sedan's. So look for the same massive Singleframe grille with the Audi rings on the upper section, angular headlamps with LED light clusters, muscular engine hood, and big vents at each corner of the bumper.

Of course, this being an RS model the said intakes will grow even larger, to the point that they will occupy nearly the entire area under the headlamps. The grille will change too. While the shape and size will remain the same, the RS9 will ditch the horizontal slats of the standard model in favor of a race-inspired honeycomb mesh. An "RS9" badge will also adorn the more aggressive nose. Below, look for a redesigned air dam, carbon-fiber winglets, and a larger splitter.

Moving onto the sides, it's here where the RS9 will get a unique look. Again, the coupe will be identical to its sedan sibling from the nose to the B-pillar, but everything will be different toward the rear fascia. As you might expect, the shorter roof will have a slanted rear glass and shorter quarter windows. By contrast, the door windows will be longer, as will the doors. Toward the back, we should see more muscular rear fenders and a shorter deck lid. The RS package will add extra vents on the front fenders, more aggressive side skirts, new wheels wrapped in low-profile tires, and a lower ride height for improved handling and a sportier stance.

Around back, apart from the modified, shorter deck lid and the aggressively raked windscreen, the coupe should retain most of the sedan's features. As you might already know, the new A8 sports slimmer taillights with pointy edges toward the outer sides and a narrower stripe that connects both light units just above the license plate. This new design should work great with the sleeker coupe design, but on the other hand it reminds me a bit too much of the current Mercedes-Benz S-Class Coupe. The RS package should also add new badges and a revised lower rear bumper that will include a diffuser and a four-pipe exhaust layout.

Overall, the upcoming RS9 should be as sleek and elegant as the Mercedes-AMG S63 and sporty enough to give the BMW M8 a run for its money.

Interior

Note: Audi A8 interior shown here.

Much like exterior, the interior will be almost identical to the standard A9, which in turn will be heavily based on the new A8. Basically you'll get a set of extra features that come with the RS package, consisting mostly of exclusive that you can't get on the A9. The latest A8 has many new features to brag about, including a version of its continuous air vent dashboard design, finer materials, and an overall cleaner, more elegant layout. The horizontal lines give the cabin a wide look, while the smooth, clean surfaces of the center stack add to the elegant appearance.

The RS9 be similar, but Audi will add a few sportier touches, including carbon-fiber trim, a flat-bottom steering wheel, and instrument cluster and infotainment screens with bespoke displays and menus. The comfortable front seats in the standard will be replaced by sportier, bolstered units for optimum lateral support during spirited driving, but the rear passengers seats should remain stock. Speaking of the rear compartment, the coupe configuration will come with a few inconveniences compared to the sedan.

For starters, ingress and egress will be made via the front doors, so getting inside and out over the tilted front backseats won't be as comfortable. Also, while legroom is likely to remain similar to the sedan, shoulder room and headroom will decrease due to the coupe-style roofline. Not as much as to make riding in the rear seats uncomfortable, but tall people will definitely have more room in the sedan.

The tech package should be identical to the standard model and include Audi’s latest infotainment system with Apple CarPlay and Android Auto and the new AI traffic jam pilot, which works like a semi-autonomous system in heavy and slow-moving traffic up to a speed of 37 mph. It also has a remote parking system through which the driver uses a smartphone app to monitor and park the car via the 360-degree camera.

Drivetrain

The drivetrain that will motivate the upcoming RS9 is still a mystery, but it will make the coupe run amazingly fast. Both the engine and transmission will come from the RS8, which has yet to break to cover, but word has it that the sedan will get its juice from either an extremely beefed-up 4.0-liter V-8 or a bigger 6.0-liter W-12. The latter cranks out an impressive 600 horsepower and 664 pound-feet of torque in the Bentley Bentayga SUV and seems to be the obvious choice here.

Output should be similar given that the most powerful A8-based model yet, the S8 Plus, had 605 horsepower and 516 pound-feet, but it doesn't necessarily have to surpass the 600-horsepower mark. With the new A8 platform significantly lighter, the RS9 would have a superior power-to-weight ratio with a sub-600-horsepower rating.

On the other hand, if it wants to give the Mercedes-AMG S63 and the upcoming BMW M8 a run for their money, Audi needs to aim for at least 610 horses. And who knows, maybe Audi will also offer an RS8 Plus with at least 650 horses, just enough for the Mercedes-AMG S65 and the upcoming BMW M7.

The W-12 engine will most likely mate to an automatic transmission, as well as Audi’s already familiar Quattro all-wheel-drive system. As far as performance goes, the RS9 should be able to hit 60 mph in 3.8 seconds or less (3.7 is definitely doable with a good setup). As usual, top speed will be limited at 155 mph, but Audi will probably offer a limited delete option that increases the benchmark to around 190 mph.

Prices

With the A9 nameplate being completely new, we can only take guesses here. But one guess I really trust is that the RS9 will be the most expensive RS-badged model yet. Actually, it may very well be the most expensive Audi in the lineup, sans the R8 supercar. How expensive? Well, it will cost more than the outgoing S8 Plus, which retails from $115,900. Significantly more I might add, because the Mercedes-AMG S63 retails from a whopping $164,750. If Audi decided to build an RS9 Plus model to compete against the AMG S65, the sticker will go well beyond the $200,000 mark.

Competition

Mercedes-AMG S63 / Mercedes-AMG S65

Essentially the only vehicle of this type on the market right now, the Mercedes-AMG S63 is a two-door version of the large S-Class. This coupe is already an iconic presence on the market, having managed to steal some attention from the much more established Bentley Continental GT. The AMG-prepped tourer comes in two flavors. The "base" model is the S63, which just received a new twin-turbo, 4.0-liter V-8 instead of the old 5.5-liter unit. This powerplant cranks out 603 horsepower and 664 pound-feet of torque, paired with all-wheel-drive for a 0-to-60 sprint in under four seconds. The other one is the S65, motivated by a larger twin-turbo, 6.0-liter V-12 with 621 horsepower and a whopping 738 pound-feet of torque at its disposal. But despite being more powerful, the S65 is actually slower than the S63 due to being a RWD-only model. Pricing for the Mercedes-AMG S63 starts from $164,750, while the S65 retails from $236,250.

Read our reviews of the Mercedes-AMG S63 and S65.

BMW M8

BMW enthusiasts have been waiting for an M version of the 8 Series since the early 1980s, but it never became reality. Instead, BMW discontinued the model and replaced with the 6 Series. But the 8 Series is set to return in 2018 and the German firm has already confirmed that it will get an M version. Previewed by a concept car that brings together some of the company's current styling cues and some futuristic bits, the production M8 will stand out quite a bit from the 7 Series. Considering what we can get in other range-topping M models, it’s safe to assume that the M8 will get its juice from a twin-turbo V-8 or V-12. Actually, there’s a big chance that BMW will offer both, just like Mercedes-Benz does with the AMG S63 and AMG S65. Output should sit close to the 600-horsepower mark to counter the 603 horses delivered by the Mercedes-AMG S63. xDrive AWD is likely to be standard, at least here in the United States. The V-12 engine could be sourced from the M760Li, which uses a twin-turbo, 6.6-liter V-12. This unit cranks out 600 horsepower and 590 pound-feet of twist in the range-topping 7 Series and should be capable of more oomph in the M8. Given that the Mercedes-AMG S65 is good for 621 horses, it wouldn’t be surprising to see BMW push output toward the 650-horsepower mark. Pricing will most likely exceed $160,000.

Read our speculative review of the BMW M8.

Conclusion

The Audi A9 will definitely be a special car and the main reason is that it will be Audi's first full-fledged grand tourer. The fact that it will also get an RS version will only spice things up and prove that Audi is finally set to take on BMW and Mercedes-Benz on all important fronts. There's still some mystery regarding its release date and drivetrain, but beyond that, both the A9 and RS9 are necessary machines in Audi's lineup and two cars that could increase the brand's visibility on the premium market.

References

Read our full review on the 2014 Audi Prologue Concept.