Presenting the most powerful production station wagon ever made.
The decision to include the RS6 Avant but not the BMW M5 Touring in this series was not an easy one. Neither company saw fit to bring the wagon versions of their super sedans to the US, and the most recent RS6 didn't make it over to the US in any form. But there was one simple fact which was just too good to ignore, the C6-generation Audi RS6 Avant holds the title of the most powerful production station wagon of all time. With that, the RS6 Avant earned a spot in this series.
The RS6 first appeared in 2002, and it remains one of the all-time great sleepers. This is because, from the outside, there was little to distinguish it from the regular A6 which it was based on. Someone who knows what to look for can spot one easily, but to the uninitiated, an RS6 doesn't appear to be anything special. It was a direct decedent of Audi's first RS car, the RS2 Avant of the mid Nineties, a 311-horsepower wagon built as a group effort by Audi and Porsche. The first RS6 was a simple enough concept, Audi bolted a pair of turbochargers to the 4.2-liter V8 which was already offered in naturally-aspirated form in the A6.
This does, perhaps, oversimplify the engineering a bit, but the original RS6 still wasn't quite as radical a departure from the rest of Audi's lineup as the second RS6 would be. This turbocharged and intercooled version of the engine produced 450 horsepower (fully 101 more than the contemporary competing Mercedes-Benz E55 AMG), as well as 428lb-ft of torque. A wide power band came from the combined use of variable valve timing and turbocharging, and peak torque was available all the way from 1,950 to 5,600 RPM. This meant that, despite the car's considerable weight, it could sprint to 60mph in just 4.6 seconds.
The only transmission which Audi could find in the VW parts bin which could handle the power from this new engine was the one out of the W12 A8, hence the lack of a manual option. The original C5 RS6 was produced only from 2002 to 2004, and when it came time to make an RS version for the C6 generation, Audi set their sights even higher. Here they again decided to bolt a pair of turbochargers to an existing engine, but this time they used a version of the V10 engine originally developed for the Lamborghini Gallardo. Just take a minute to let that idea sink in, a station wagon with a twin-turbo Lamborghini engine under the hood.
This new 571-horsepower power plant made the RS6 the king of the super wagons, although by this point the competing wagons were closing in on Audi's power figures. Not only that, but the RS6 now also has to compete with the Cadillac CTS-V and the Jaguar XFR, both of which also come in wagon form. The C6 RS6 has an electronically limited top speed of 155mph, but Audi's engineers are said to have gotten it up over 200mph on the test track. Some have criticized the C6, saying that Audi put too much emphasis on comfort, and as such strayed away from the more stripped-down and performance-oriented spirit of the RS cars.
These critics may have something of a point, but still, twin-turbo Lamborghini engine, that can help you get past a lot. Suspension for the RS6 is stiffened up more than the regular A6, and massive brakes are fitted as well. These top out on the C6, where there is an option for 16.5-inch carbon composite rotors squeezed by eight-piston calipers. Brakes of this size are capable of bringing the RS6 to a stop fast enough to cause pain to the vehicles occupants. There is once again only an option for an automatic transmission, and the price increased dramatically over the C5. Weight is up too, coming in at about 4,500lbs in Avant form.
Just the same, it is an amazing machine, and a person would really have to work hard in order not to see past the downsides. This second RS6 also had a short lifespan, although this was again by design, lasting only from 2008 to 2010. A 2014 model is currently in the works, based on the new A6. We may not get this one in the US either, and it's pretty much guaranteed that we won't get the Avant version, but there is now another option which looks realistic. The new A7 is based heavily on the A6, being essentially identical mechanically and differing only in the body shape.
Audi is there developing an RS7 alongside the new RS6, and it's likely we'll get the RS7 no matter what happens with the RS6. True, the A7 is more of a hatchback than a wagon, but it's still some exciting news.