I greeted this news with a smirk at first, and then, after half a second of thoughtful reflection, decided that adding all-wheel drive, or as BMW calls it, xDrive, to the Bavarians mighty M5 is probably a good move. BMW can lose all notions of restraint from time to time, especially when it comes to the M5. They have been known to put all sorts of crazy drivetrains into the M5, and sell them to anyone whose considerably large check didn’t bounce.
So maybe maximizing power delivery and traction isn’t that bad of an idea?
The M5 has, from the get go, been about what’s under the hood first, last, and always. Yes, they have always handled very well, considering their size and shape and especially weight. And yes, they have always had exemplary brakes, since Germans have a fetish for those. But, the M5 engine on the other hand, has always been the car’s feature party trick. The first M5 had the same plant from BMW’s M1 supercar. That would be like Ford taking the engine out of the current GT and dropping it unaltered into the engine bay of a Crown Victoria. (Actually, that sounds like a pretty good idea, but I digress.)
And that was where the M5 started from, and it got only more nuts from there. BMW put a V10 in the M5 for a few years, and it had the maintenance needs of the space shuttle’s APU. Great car, sure, but when the factory says, “remove engine and ship it back to us in Germany,” as a matter of routine maintenance, perhaps you’ve wrapped things a bit too tight.
The latest M5 is motivated down der Bahn by BMW’s 4.4-liter V8 engine with a TwinPower Turbo set up. The plant features higher injection pressures, new turbochargers, more powerful lubrication and cooling systems, and a modified, lighter exhaust system. This is, in a way, throwing technology at a problem, rather than some of the brute force answers of the past, but hey, if it works, it works.
What is noticeable about this latest M5 variant is the all-wheel drive system. BMW’s xDrive has been tweaked and proven on their range of SUVs, and also on lower siblings in the corporate stable (3 Series and such), but now the Bavarians are asking it to take a big bite of the performance apple.
Selection & Strength
Like a lot of modern cars, especially performance oriented modern cars, the latest M5 has a number of driver selectable traction and performance schemes to choose from. For example, the M5 has five different configurations based on combinations of the Dynamic Stability Control (DSC) and M xDrive modes. The driver can select from DSC on, M Dynamic Mode (MDM), and DSC off, which are DCS modes – then 4WD, 4WD Sport, and 2WD, which are M xDrive modes. The hardware bits and pieces of the M xDrive are based on those of the BMW xDrive all-wheel drive system and the Active M Differential. M-specific driving dynamics control software then ensures, ahem, “innovative deployment.”
The whole drivetrain has been reinforced for greater strength and rigidity to accommodate the higher torque and rear-biased configuration, along with the 2WD option. The transfer case splits the engine’s drive between the front and rear ends in an adjustable ratio; the Active M Differential takes care of splitting the grunt between the rear wheels. This is all factored in by a bunch of ones and zeros and computers so the rear diff can vary from zero and 100 percent lock, as the situation demands.
But here’s where things get really fun. BMW refers to the selectable power delivery and traction schemes as “à la carte handling dynamics” and that’s a very good way of looking at it. Every time you start your BMW M5 it defaults to 4WD mode with DSC on. Which is fine and dandy from a gearhead perspective, because even in this basic mode, you get a certain amount of slip at the rear wheels to generate agility. Coupled with the M xDrive, you get palpable advantages accelerating out of corners.
And yes, there’s even more (and cooler) variations to be had within the AWD system, but the real fun comes up when you turn the system off. Unlike Audi’s sublime quattro set up or Mercedes-Benz with their 4Matic, the M5’s can be turned off. With the DSC deactivated, there is a choice of three modes: 4WD, 4WD Sport, and 2WD, but it’s the 2WD setup we’re talking about here, cause it’s bound to be the most fun.
As the name implies, in 2WD mode, all the power is sent to the rear wheels. This results in, as BMW puts it, “the experience of driving a high-performance sedan with rear-wheel drive only, delivering a pure form of driving enjoyment that captivates in its own unique way.”
You know, the way any near-death experience in low traction situations is “captivating.”
Best of Both Worlds
Keeping the beast going in the desired direction is all down to your right foot, both hands, and that Active M Differential (and a few more digital nannies thrown in, but why ruin a good analogy). So BMW’s new M5 with M xDrive is literally a “have your cake and eat it too” situation. You need all the traction you can get cause that rain from the morning commute has now turned to snow on the evening drive home? BMW’s got you covered. Nobody around on that winding back road on an early Sunday morning? BMW’s got you covered there too.
BMW even asked DTM driver, Timo Glock to offer up an opinion.
“I often drive long distances and I need plenty of room for my family, but I wouldn’t wish to give up the chance to explore the car’s sporting character,” he said. “With M xDrive, not only can the new BMW M5 be steered with the usual precision and agility, it also offers me something I really appreciate, living in Switzerland: a noticeable boost to traction and controllability – even when driving in particular environmental conditions, such as wet weather and snow, and in both everyday driving situations and when pushing the car to its performance limits.”
Now, re-read that quote and keep in mind that Timo is, well, Timo’s a little der spinnt. He used to race in F1, where he picked up the nickname of “Mr. Nine Millimeter,” given both his last name and apparent affinity for rap music. But he had a tendency to wreck cars, so he got fired. So then BMW picked him up and let him loose in the DTM series, where that sort of thing isn’t exactly discouraged. Anyway, it puts that “when pushing the car to its performance limits,” quote into a bit greater context.
Or, to put it another way, if Timo can use this thing without killing his entire family, it must be great!
Tony Borroz has spent his entire life racing antique and sports cars. He means well, even if he has a bias towards lighter, agile cars rather than big engine muscle cars or family sedans.
Photos & Source: BMW of North America, LLC.