Boz the dog is perhaps the ultimate station wagon road tester. Since he began making a serious dent in my personal finances back in 2004, this trusty but sporadically disobedient Weimaraner has passed opinion on the finer points of the competencies of station wagons from most manufacturers. Now, every dog has his own speciality, and being of German descent, Boz's specialty is speed; his acute understanding of yaw and lateral acceleration--and how to combat them with appropriate lean angles--has made him famous in canine social circles. Allegedly. Since Europe has recently been subjected to three of the fastest wagons ever to crease the pavement, it seemed to make sense to enlist his services. Besides, he'd have eaten the furniture if I'd left him at home.
I am well aware that the superheated station wagon is not an automotive staple in the United States--of the three grocery getters gathered here, only the Mercedes-Benz E63 AMG is sold there. Here in the United Kingdom, the situation is rather different, so before we delve into the current marketplace, allow me to explain why Great Britain has a fascination with such vehicles.
For starters, the U.K. is a nation of car lovers and dog lovers. Any vehicle that allows these pastimes to be enjoyed simultaneously is a good thing. Despite the current SUV epidemic, most of us also enjoy our performance when it's presented in a less ostentatious form. People respond better to family-oriented shapes, and in a country blighted with road rage, that is a bonus. The superwagon is the best method yet devised for cloaking unnecessary performance potential on public roads.
How curious, then, that as the muscle wagon blossomed over the past decade, the one company you might expect to be at the forefront of an emerging niche decided to stay away from the party. BMW did build a Touring version of the E34-series M5, but fewer than 1000 were sold, and the company decided that demand wasn't strong enough to justify an E39 M5 wagon. It vehemently denied the existence of the new one until we recently saw an M5 wagon lapping the Nrburgring at speed.
This strange twelve-year hiatus allowed Audi to become an unexpected market leader. I say unexpected because of the way Audi's alarmingly fast wagons have been embraced by the knowledgeable few, while at the same time, its sedans are routinely dismissed by equivalent Mercedes-Benzes and BMWs in group-test encounters. It's one of life's strange phenomena, and it can be explained like this: among an affluent dog- and car-loving population living on a predominantly damp island, fast all-wheel-drive Audis are sweet. They work so well that we Brits have tended to forget the shocking ride quality, the intolerably sensitive brakes, and the vapid steering.
Then, last year, along came the latest RS4 Avant. I suspect this is the car that forced BMW to reconsider its BWS (Ballistic Wagon Strategy) and get things moving for the current M5. Here's an Audi that retains all of its dependable Audi-ness but has been ramped up with a 4.2-liter V-8 that twirls beyond 8000 rpm, a steering rack willing to communicate with the driver, and the option of ceramic composite brakes. Audi might as well have called it the "What M3?" for the manner in which the RS4 has undermined sales of the BMW and forced a rethink on the general subject of Audi dynamics. Boz, who has spent the past seven months in the back of my RS4 Avant, admires the car's secondary ride and unbeatable all-weather performance.
But if 420 hp sounds lively for a wagon, there is still more ridiculousness around the corner. As you will know, Mercedes didn't feel it had stretched the boundaries of common sense quite far enough with the supercharged E55's 469 hp, so it roused AMG's lunatic department and issued orders to have that car's weakling powerplant replaced by a normally aspirated, 6208-cc V-8 that produces 507 hp. Even Boz's ears lower perceptibly at the thought of the E63 on full afterburner.
The reason for this story, however, is the new M5. If the RS4 and the E63 bring their own unique talents to the table in the form of four-wheel drive (Audi) and a slick autobox (Mercedes), then the M5 wagon sits somewhere in between. American customers won't be offered this practical beastie; instead, they must make do with the 535xi. But they were sensible enough to inform BMW that the new M5 sedan's SMG transmission spoiled an otherwise excellent machine, and the company has acknowledged this by wedging a six-speed stick into the old girl. And then dictated that the stability control must remain on at all times. Heigh-ho, Americans get the proper gearbox, Europeans get the wagon. All is fair in love and global model structures.
So, this car has an SMG--a paddle-shifted, hydraulically actuated seven-speed manual, or whatever else you want to call it. I tend to call it rubbish, but let's not prejudge this newest application. The wagon has the identical 500 hp as the sedan, and its body is unchanged, aside from the wagon parts. But there is some funniness going on underneath the rear axle: a cross brace sits underneath the differential, and the exhausts run under it. The result is that they're very low indeed, low enough to snag on stuff. We shall see if this poses a problem.
Any sensible assessment of practical, versatile family wagons should of course begin with some kind of customer clinic. So we headed straight to a test track. Despite my best attempts to persuade security that Boz was an integral part of this process and that his doglike appearance shouldn't detract from his skill base, they enforced the "no quadrupeds on site" clause. Whereupon Boz was tied to a tree adjacent to the security men's vehicle--which I saw him lightly sprinkle as we headed to the mile-long straight.
Weight may be on the RS4's side--and, yes, it does feel strange saying that in the context of a 3771-pound vehicle--but it takes a walloping when it comes to standing starts. All-wheel-drive traction on a dry surface isn't much of a benefit in these disciplines, and whichever way you approach the manufacturer-supplied figures, the RS4 just isn't as fast as the M5 and the worryingly cogent E63. Even so, 0 to 62 mph in 5.0 seconds means this is a very fast car. But the BMW's mark of 4.8 seconds belongs in an even more grown-up paddock. And the next time a Porsche 911 driver considers tangling with an E63, he would do well to remember that the driver of this particular family holdall has access to 4.6-second 0-to-62-mph runs at the stretch of a right leg. Simply shift into D, depress the accelerator, and go. The first time I floored the E63, I had to stop, get out, remind myself it really was a wagon presenting such potency, and then resume. Performance of this magnitude deployed in a humble wagon feels wonderfully irresponsible in a way 507 hp housed in something low and penile never could. Loading it with people and junk and then finding out what lurks in front of that gearbox is like discovering that your grandma is a crack addict.
Keep to the straightaways in the Benz, and it will make you question the other cars' claims to ultimate-wagon status. Being the similar pair in size, and archrival brands to boot, the E63 and the M5 have a grudge match to settle. And, for all the BMW's undoubted provenance, the E63's brutal simplicity exposes the M5 at first. The E63 is a devastating plug-and-go device, its engine sounds fantastic, its cabin is intuitive, its body is easily the most practical, and it looks plain dangerous.
Whereas the Merc's performance arrives virtually unannounced, you have to extract the big numbers from the M5. Its V-10 needs more working than the Mercedes V-8, but beyond 5000 rpm it summons an urgency that no other Labrador-lugger could hope to match. Each time I shifted from second to third at 8000 rpm and watched the head-up speedometer click into triple digits, I completely forgot that I was driving a large wagon, because the very nature of the experience, not to mention the thrust on offer, didn't tally with the car's body style.
Unsurprisingly, the M5 is very good at going fast. Its spring and damper rates are better tuned to the rigidity of its body shell than are the E63's--at road speeds, it feels the same as an M5 sedan, which is quite an achievement. Such composure sat well with Boz, who gave the car high marks for ride comfort but found the chrome load fasteners rather cold on his behind. Priceless feedback, as ever.
The Mercedes is noticeably oversprung and overdamped: the primary ride is as good as the BMW's, making it as comfortable at freeway speeds, but jagged edges harshly ping through the E63's cabin, while the M5 smooshes them under its Michelins. And this is with the softest of the three available damper settings. Boz was unimpressed with the general jiggle out back, but he enjoyed the spacious surroundings. The M5 also steers better with its faster, more direct rack.
So, where does the little Audi fit? The performance disadvantage isn't nearly as pronounced on the road, where the RS4 can still be considered indecently fast. In fact, this car refuses to follow the script written by a dozen fast Audis of yore (massive urge, crap everything else) in being a truly rounded road car. It steers as well as the M5 and has a slight advantage in ride comfort. Upsetting its composure on a public road would require abject silliness from the driver. An Audi that handles as well as an M5: who'd have thought it?
Compact dimensions are also a bonus for Boz, whose lengthy notes on the subject show a predilection for these slightly smaller wagons, because they offer him better potential for bracing under cornering loads.
And lest we forget, this is on a dry road. On wet asphalt, of which Britain has plenty, the M5 and the E63 wouldn't be able to see where the RS4 had gone. I still don't believe this rear-biased four-wheel-drive nonsense that Audi goes on about: the RS4 may be the best-balanced, least-understeering car it has produced since the early 1980s, but it still feels no more rear-biased than Brigitte Nielsen leaning over a low guardrail.
Until the RS6 arrives with its reputed 550 hp, this is the biggest superfast Audi, and of course, it doesn't offer the space of the other two cars. The rear cargo compartment is narrower and shorter, and the cabin is far cozier. The 5-series wagon body is sizable: few families should need more space, even if the rake of the rear window somewhat impedes Boz's headroom. However, any family moving from the E-class to the 5-series will notice the difference. The E63 makes the others feel like part-time hatchbacks for ease of use and sheer capacity. Its cargo area is enormous and its rear seats roll forward to give a huge, flat load area, whereas the other two have rear seatbacks that merely tilt forward.
And yet in America--the land of unprecedented consumer choice, the land that I'm fairly sure invented the station wagon concept--you won't have the chance to buy either the M5 or the RS4 in wagon form. Clearly, the marketing goons have run their spreadsheets and the numbers don't stack up, but in reaching such a conclusion, they're denying Yankees access to some of the most amusing machinery ever built. Imagine the irreparable damage caused to the 911 driver's libido as he guns his sports car to the limiter in each gear--only to see Boz calmly surveying the Porsche's front light clusters through the rear window of a rapidly disappearing M5 wagon. These moments--the ones where supposedly heavyweight sport machines are humiliated by the family man's vehicle of choice--are, more than anything else, the joy of these cars.
So I suggest that Americans begin campaigning for their introduction with immediate effect. A Dodge Magnum SRT8 may have the space, some of the thrust, and a much lower price than the E63, but it doesn't feel quite as capable. Each of these German machines is truly a master of any-situation performance.