Compare the coupe versions of these competitors side-by-side here.
What's in an R?
Many features, both functional and cosmetic, distinguish an RS from an S. Key among them is a 4.2-liter V-8 engine, also found in the Audi R8, that's wedged in place of the S5's supercharged 3.0-liter V-6. Last seen in this model line in the 2009 S4, the V-8 is back, but bringing almost 100 hp more than it had back then. With it comes EPA-estimated gas mileage that's nearly as bad as it was before — but only 2 to 3 mpg worse than the current S5 in combined city/highway driving — 16/23/18 mpg city/highway/combined — but better than the M3 (16 mpg combined), C63 (15 mpg) and CTS-V (14 mpg) coupes. All the models cited except the Caddy require premium gasoline.
Quicker Than … Stink?
But enough about fuel efficiency. The RS 5 is designed to satisfy drivers, not the freakin' EPA. And satisfy drivers it does. Scribes sometimes declare a car goes as fast as stink, which sounds colorful, but stink doesn't always go very fast, now does it? (Probably depends on the wind.) The RS 5 goes quicker than both stink and the S5, and roughly as quick as the M3 — an estimated zero to 60 mph in 4.5 seconds, according to Audi. Our friends at PBS' "MotorWeek" did it in 4.3 seconds.
With its standard all-wheel drive, the RS puts its power to the pavement as well as any car could. Whether equipped with 19- or optional 20-inch wheels, the RS 5 comes with summer performance tires, so even if the all-wheel drive makes you think this is an all-season car, the only way it's going to happen is if you also buy a set of winter tires at several hundred bucks apiece.
Truly a multisensory experience, the RS 5 has a terrific-sounding engine and exhaust — at least with our car's sport exhaust option, which also includes black tailpipes. Only the C63 AMG compares. Perhaps my favorite aspect of the RS 5 is how its exhaust barks upon downshifting when in the Sport mode, which keeps the lightning-quick S tronic seven-speed, dual-clutch automated-manual transmission in lower gears and ready for action. Even if you let the car coast to a stop, in this mode the transmission downshifts through the gears and barks away each time.
Down One Pedal
What the RS 5 doesn't provide is a stick shift. Major bummer. The fact that true manual transmissions are disappearing among normal cars is understandable. It's tougher to accept in the highest-performance cars, whose potential buyers are the mostly likely to appreciate a proper stick. Ditto for the C63 AMG.