"And every mile on the Nordschleife equals nine miles on the street," says the RS5's product manager Anthony Garbis.
The result is one of Audi's quickest and fastest four-seat coupes ever.
Unfortunately, Arizona's State Police in their white Ford Explorers have little interest in us sampling the RS5's 174 mph top speed or its 3.7-second 0-60 mph acceleration. Under crisp blue skies, we're northbound in a Sonoma Green RS5 (an exclusive color) on Route 87 toward Payson, a sleepy enclave in the Tonto National Forest made famous by author Zane Grey in the 1920s. The wide-open four-lane dips, dives and bends, but its 55 mph speed limit is strictly enforced, and Arizona's boys in blue armed with instant radar have just written up two in our group for excessive speed. According to the victims, the officers wrote the citations while quizzing them about the RS5's specs. Nice.
The A5 family now offers eight models in three bodystyles, and it makes up 10 percent of Audi's sales in the United States. RS models, which also include the RS3, RS7 and TT RS, are maximum performance vehicles that sit at the top of their model lines and battle BMW's M products and the gang at AMG for enthusiast desires and dollars. The 2018 RS5 is aimed squarely at the BMW M4 and Mercedes C 63 Coupe.
Like its competition, the Audi RS5 has ditched natural aspiration for turbocharging. Gone is the model's high-revving 4.2 liter V8, replaced by an aluminum 2.9-liter, twin-turbo V6 it shares with the Porsche Panamera 4S. Audi Sport has tweaked the engine for greater performance, lowering its compression ratio from 10.5:1 to 10:1, adding duration to its camshafts, and adding boost — up to 21.6 psi. The gains are really on the torque side. In the Audi, the engine is rated at 444 horsepower at 5,700 rpm and 443 lb-ft of torque at 1,900 rpm, while it's rated 440 hp at 5,650 rpm and 405 lb-ft of torque at 1,750 rpm in the Porsche. More important, the boosted V6 produces much more torque than the old V8's 317 lb-ft at 4,000 rpm, and it's 66 pounds lighter.
The engine's packaging is also unique to the Audi, and includes stainless steel intake tubing for improved flow and an oil cooler that's mounted parallel to the ground ahead of the radiator to generate 6.6 pounds of additional downforce.
The RS5's seven-speed dual-clutch transmission is also history, replaced by a ZF-supplied eight-speed automatic. This is the same transmission used in the RS7, and Audi made the switch because the dual-clutch can only handle up to 370 lb-ft of torque. Controlling the temperature and durability of the unit's torque converter, which is 10 pounds lighter and unique to the RS models, required the engineers to dial down the engine speed allowed by the RS5's launch control from 4,000 rpm to 3,300 rpm. But the additional torque of the V6 and the transmission's shorter ratios more than make up for it, quickening the RS5's 60 mph sprint from 4.5 seconds to just 3.7, which Audi says is quicker than the competition.
The RS5 sits a quarter of an inch lower than the S5, and although it uses the same A-arms, it utilizes wider brake hubs and less wheel offset to widen its front track by 0.4 inches and its rear track by 0 .8 inches. Dynamic Ride Control is optional along with a Sport Exhaust System for an additional $3,350. The optional suspension, which is also available on the RS7, uses steel springs and adjustable dampers connected to each other diagonally through hydraulic lines and a central valve. It increases the pressure in the diagonally opposed dampers (right front and left rear) to decrease roll during cornering. The oil reservoirs, along with the battery, are mounted in the trunk to optimize the coupe's weight balance.
Audi Drive Select is standard, and the RS5 rides well in Comfort mode. On Arizona's smooth roads the suspension soaks up larger impacts cleanly, but you can still feel enough grit of the asphalt in the seat, steering wheel and floor to know you're not driving a standard A5. The RS5 gets standard 19-inch wheels, which weigh 22.5 pounds a piece, and optional 20-inchers that weigh 27 pounds.
Switch to Dynamic mode and the RS5's suspension, according to Matthias Noethling, the technical project manager on the RS5, transforms into the stiffest suspension Audi offers in the United States except for the R8 V10 Plus. In Dynamic, the ride can be bouncy, although it's never really harsh. Noethling and his team have still managed to round off the edges and keep things refined over broken pavement.
Dynamic mode also sharpens throttle response, changes the transmission's shift points, ups the steering effort, and fixes its ratio at a very quick 13.5:1. In normal mode the ratio is variable between 16:1 and 25:1. Dynamic mode also cranks up the engine's sound. In Comfort mode Audi artificially amplifies the engine's resonance inside the cabin below 3,000 rpm, but it's still in the background. Above 3,000 rpm, flaps in the RS Sport Exhaust system open to give you more natural audible feedback, but in Dynamic mode they're always open and the V6 has an enjoyable burble, even at low rpm. RS5s with the RS Sport Exhaust system are distinguished by their black tailpipes.
Risking a run-in with Arizona's finest, we pushed the RS5 well past the legal limit on more than one occasion. The eight-speed is quick with a few downshifts, and the turbo V6 pulls hard to its 6,700 rpm redline, where the transmission clicks off a clean and crisp gear change. Nail the throttle at 70 mph and the Audi's acceleration pushes you into its firm, well-bolstered RS Sport Seat and holds you there. The transmission snatches fifth gear at 94 mph, and the thrust continues essentially uninterrupted. Keep your foot down and the coupe is well north of the century, stable and relaxed, before the next gear change. Without the Dynamic Plus Package, Audi limits the RS5's top speed to 155 mph — more than anyone needs, of course.
We also explored the Audi's handling on a few tight and twisty side roads. Although it's heavier than the BMW M4, the 3,990-pound RS5 hides its heft well with quick response and impressive levels of grip. It likes to be tossed from corner to corner and puts the power down so nicely that you don't have to be delicate with the throttle.
The standard power distribution of its all-wheel drive system is 40 percent to the front tires, but it can send as much as 70 percent to the front and up to 85 percent to the rear. In corners, the system's Quattro Sport Rear Differential, which is a completely mechanical unit, can also send all available rear torque to either rear wheel, and in Dynamic mode it transfers more torque to the outer rear wheel to help the car turn. Audi also allows you to shut off the coupe's stability control, but there's also a Sport setting with more aggressive tire slip thresholds. These systems all work as advertised, fixing your mistakes without spoiling your fun or scrubbing speed unnecessarily. Use the paddle shifters and the transmission matches revs perfectly.
And its brakes are massive. The RS5 gets 14.8-inch front cross-drilled rotors with six-piston calipers in black or red with the RS logo. Those are bigger front rotors than you'll find on a Porsche 911 Targa 4 GTS. Larger carbon ceramic front brakes are available, and cars with the option get a tire-temperature readout on the instrument panel.
From the curb, the new RS5 packs attitude. Audi has bulged out its fenders over half an inch, dressed its mirrors and grille surround in matte aluminum trim, added larger air intakes to the front bumper, gloss black side sills to the doors and widened the grille which gets a black honeycomb mesh. In back there's a diffuser, large oval exhaust pipes and a black lip spoiler. But the coolest part is the sizable QUATTRO script on the front spoiler. An older guy in the new BMW M550i nearly broke his neck checking it out.
The new Audi RS5 goes sale this month at $69,900, and topping out around $90,000 with every available option. As good as the new RS5 Coupe is, and it is incredibly good, that's a grand or two more than a BMW M4 or a Mercedes C 63, both of which are rear-wheel drive, and you can still get an M4 with a manual transmission. We're not sure if a convertible is in the works, but after the drive, which we managed to complete without a run-in with the law, we did ask Garbis about the possibility of an RS5 Sportback. "An RS5 Sportback would be a nice addition to the A5 family." he replied with a smirk. "I'd drive one."