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      05-13-2012, 05:44 AM   #1
GTR-Dad
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Drives: 2012 M5 - DCT
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An enthusiast's F10 M5 review

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Have you ever looked forward to something, built it up in your mind, and then been let down or bitterly disappointed? I've done this to myself with movies, trips, gadgets, and yes - even cars. However, after seven days and 2400 km on German backroads in a new M5, I can tell you this is definitely NOT one of those times. My expectations were high and they were fully satisfied!

This review is focussed on how the car works, not how it looks. For the curious, my spec is Singapore Grey with black Full Leather interior. No rear seat entertainment (I'll provide the entertainment thx) and no night vision. Otherwise fully optioned.

Every new car experience starts at a dealership and good experiences are nice to find. Hats off to Doug, Jack, and the team at Edmonton BMW for making the purchase and European delivery experiences uniformly positive.

The BMW European Delivery experience is polished and everyone at the Welt looked after us very well. The presentation of the car was memorable, but paled in comparison to the driving experience, which, for me, is all about engagement with the road via the car. Steering feel, suspension setup, throttle response, and gear box function along with mechanical grip define what I care most about.

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The sum of the parts is a very impressive 'whole'. The driver is well-positioned to see and feel everything required to attack the road, or when the opportunity presents itself, to sit back and cruise in comfort. Power is, to borrow a term, 'adequate' even while observing the BMW recommended run in limits of 4500 rpm and 'permanent top speed no greater than 170 km/hr'. (What does THAT mean? I took it say speed should not exceed the limit for very long...) Steering feel is decent by modern 'isolate the driver' standards, and the adjustability of throttle, gearbox, and damper response covers a range that ought to satisfy
almost everyone.

Gearbox

The M5 is spec'd with a 7 speed dual clutch automated manual gearbox rather than a 'proper' manual with a clutch and gear shift. This choice represents the most difficult part of ordering the car. Every other car I've owned has required me to take a more active role in changing gears, and it was really out of respect for the BMW engineers' design intent that I decided to try the dual clutch box. From where I sit right now, I think I made the right choice, but I've got a bit of learning to do before I can claim to drive this car the way I want to on the race track.


Efficiency mode in either auto or sequential configuration does a great job of minimizing fuel consumption and softening the edge that comes with more assertive settings. Comfortable, smooth, and relaxed are the correct descriptive words. I didn't engage efficiency shift mode very much.


Sport Plus shift mode promises the ultimate response and performance experience. Right? That's where I started and it certainly wakes the car up! Shifts are crisp, solid, and perhaps even a bit harsh. (I might have been more decisive about shift harshness if I hadn't driven an Aventador on the track a couple of months ago. Corsa mode, Lamborgini's version of Sport Plus, under WOT acceleration is a recipe for whiplash. Fun, but worryingly hard on the drive train and occupants alike.) I didn't use Sport Plus in auto mode as the shift points were significantly in excess of run in rev limits, but I think I'll be manually shifting this car most of the time anyhow. My only real beef with Sport Plus manual is with down shifting. Although there's an appropriate throttle blip to match revs, when the clutch reengages, engine braking is significant enough to upset the car, particularly in trail braking / late downshifting situations. A good heel/toe downshift in a proper manual is smoother and provides a more natural opportunity to modulate engine braking with a bit of maintenance throttle. I expect I'll learn this skill with the dual clutch setup, but not this week.


Sport shifting speeds up the gear changes substantially compared to efficiency, and remains decently smooth. Smooth enough to keep your passenger's head from jerking forward during shifts, and smooth enough to keep 'shock loading' out of the gear train's load history. In automatic configuration, the shift map is remarkably sympathetic with enthusiastic and spirited driving. If you get caught needing to attack a road in this mode, you'll find that crisp shifts at reasonable but assertive revs will get the job done. If you lift, the car will hold the gear anticipating reapplication of the throttle and will upshift only when moderate throttle is applied. Downshifts are a little slower than Sport Plus, but the payback is that engine braking is less obtrusive and the shift is smoother. Almost as smooth as I'd do it myself - on a good day. Of course not every downshift in a proper manual is perfect, and I'd never want to go up against the dual clutch system in a contest of consistency, but then again, striving for the perfect downshift - every time- is part of the joy of driving and when the car does it for you, something is lost. (Reflective pause.....)

Throttle reponse
BMW has done several clever things to minimize the time between when the driver provides throttle input and when torque is delivered. Let's call this delay 'lag' as a catch all term, although some will recognize there is a difference between time required to achieve the rpm necessary to spool the turbos and the time to transition from off-boost to on-boost at engines speeds greater than the spool rpm.
Key items that maximize responsiveness are:
- Minimized exhaust manifold length achieved by positioning exhaust manifold and turbo chargers inside the V. Shorter length reduces response time.
- Efficient transfer of exhaust energy to turbo chargers by delivering correctly timed individual exhaust pulses to turbines. A combination of a clever cross flow manifold and twin scroll turbo chargers accomplishes this one.
- Minimized hot side volume achieved by use of air to liquid charge coolers (rather than an air to air unit) improves response by reducing the intake air volume that needs to be compressed.
- Wastegate programming provides the option of leaving the wastegate closed to keep the turbos spooled for quick response or leaving waste gates open to minimize exhaust back pressure and improve efficiency. (I want better control of this!)

In operation, to a driver conditioned to tolerate turbo lag in exchange for the benefits, the M5 feels very responsive. Particularly during sprited driving, it is difficult to discern the delay between commanded and delivered torque. Off-boost response is a slightly different story. My butt dyno says that the waste gates remain closed (keeping turbos spooled) in Sport and Sport Plus throttle settings, but not in the Efficiency setting. This would all be fine and good if I preferred a map that provides more throttle during the initial throttle opening, but I don't. I prefer a map that enables me to modulate the (substantial) available torque rather than slamming me with the excitement of more throttle than I indended, perhaps during a corner exit. In an effort to evaluate 'lag' in normal highway driving, I measured lag in top gear at about 120 km/hr and found it to take nearly a second with the Effiency throttle map and less than half than in Sport/Sport Plus to go from 'easy cruise' to 'full boost'. In the world of turbo charged cars this is very very good, but to those accustomed to NA engine response it may be disappointing. In the words of a good friend who drives an E39M5, "By the time the throttle is fully opened, the car has been accelerating for quite some time!" This is an area where the downside of forced induction has been minimized, but not quite eliminated.


Steering

Steering feel get's a passing grade, but with some qualification. Modern cars seem to isolate the driver from the road so consistently that any feedback through the steering wheel is a welcome surprise. Irregularities in the road come through, but the feedback I really appreciate through the steering wheel relates to available grip through the front tires. For example, I've driven cars where steering weight is directly and significantly proportional to the amount of steering input, until grip starts to run out at which time steering effort drops off. This is even more meaningful than feeling the road surface through the wheel. In any case, I was unable to detect a meaningful difference in steering feel between the three available settings. Steering effort definitely increased with Sport, and even more with Sport Plus, but without a corresponding increase in direct feedback from the road surface, the increased effort seems pointless.Perhaps things change at the limit... I'll need to find out!

Suspension
Suspension setup has a profound influence on vehicle dynamics, NVH, and (after tires) even mechanical grip. In comfort mode, the M5 is, well, comfortable and well behaved. The car feels responsive in most road situations and it's only during hard cornering, particularly with rapid left/right transitions, that body roll becomes evident and a quick change to Sport damping is required. The car then becomes more responsive to steering inputs and feels more stable and sure footed. Fun, to be sure! Although I used Sport Plus damping on occasion, I don't have any useful observations, so I'll leave it at that. Past experience would suggest that in Sport Plus, connection to the pavement will be superior on smooth roads, but suffer on irregular surfaces.



Driver Aids

Traction and stability control are, in my opinion, features to be used only while you're texting, sleepy, or otherwise disabled. Fixing driver errors with computer intervention is a great way to train bad drivers, one corner at a time. They work, but definitely take something away from the driving experience. 'The thrill of pressing the accelerator' is much much less satisfying than 'the thrill of driving'. Anti lock braking falls in this category for me as well, and I will not entertain discussion on this topic. If you feel the need to debate this, go read some other review.


Opinion pending
On the topic of braking, I can only observe that brakes are strong and well suited to road use as I really didn’t push them hard on the track. The same goes for the cooling system, which didn’t get much of a workout given my (more or less) adherence to run in limits.

Real Life
Moving beyond the analytic, real-world driving experiences serve as the most reliable demonstration of what the M5 is all about. The first such experience came on a downhill section of a mountain pass in the German Alps. Many corners were relatively long radius for this kind of road, rewarding moderate speed/high lateral g capability, and several were tight hairpins that required low speed and offered great opportunity to evaluate vehicle dynamics in extreme transient load conditions. My approach to driving fast with a strange car on strange roads is to work up to the limits gradually. The M5 was sure footed and kept on whispering 'trust me', which is so much more reassuring than 'you shouldn't have done that', or 'don't ever do that again'. We worked up to some pretty high braking thresholds with turn-in initiating just as brake pressure was eased off. The car responded predictably and the road ended before any limits, besides those of common sense, were reached.



The next test of this particular limit occurred at an old race track North and West of the beautiful city of Koblenz. The North Loop of the Nurburgring was open to the public for only a single day during our driving vacation window, so it would take more than rain and common sense to keep usaway. My approach to keeping it between the lines by working up gradually served us well. I braked early and slowed more than (I thought) was necessary for the first real corner only to find that the available grip was much much less than I could have dreamed. Maybe it was the texture of the track surface. Or perhaps it was the wet conditions (although there was no standing water here) combined with the Michelin Pilot Sport tires that initiated what felt like terminal understeer. In any case, it was a wake up call that driving this track in the rain, with five hundred plus horsepower, relatively slick tires, and (yes) no traction or stability control was an activity to be taken seriously. Grip varies dramatically around the track and there were a couple of heart stopping moments when the combination of torque, corner radius, and friction coefficient conspired to break the rear end loose (once violently!), but the car is really quite catchable and if you pay attention, this wolf is unlikely to bite. No track records were set, but a ton of fun was there for the taking! The wet conditions kept many people away and for most of the time, the track was mine to experience without the distraction of faster and/or slower cars. The end result was a tremendously positive experience and a healthy respect for both the M5 and the Nurburgring. (Tick off one bucket list item!)









Driving 2400 km in 6 days made for a few longish drives and offered the chance to evaluate the M5 as a long range touring car. Given the 'permanent top speed' restriction, the autobahn sections were taken moderately, but demonstrated comfort and composure beyond what I've experienced in a car. Have you ever found yourself tired of sitting in the same position and wished for an opportunity to change things up a bit? You can readjust the seats, but that only goes so far - admit it. You need to either stop to stretch your legs or.... turn on the seat massage funtion! I am not entirely sure what I expected when I pressed this button, but can assure you I was both alarmed and delighted! The slow, strong, undulating massage relieved tension, restored circulation, and offered a welcome diversion to the tedium of 170 km/hr autobahn cruising. My only advise here is to avoid first-time exposure in traffic.


For those who care about fuel economy, and who doesn't - really, the M5 averaged 12.5 l/100 km for the trip, including 80 km on the track and many many full throttle squirts. The helpful 'efficiency dynamics' gauge (previously known as that annoying fuel consumption meter) claimed 14 l/100 km efficiency at 170 km/hr. Pretty decent by everyday supercarstandards! There's also a regenerative braking function that is probably set up to charge the battery preferentially during deceleration. It shows up on the efficiency dynamics gauge during trailing throttle (so you know what's going on?) and is quite noticeable in lower gears. and when it trips in and out, it actually feels much like a gear change. A little weird, but if it saves the environment it must be good.


Much has been written and debated on the topic of sound in the F10M5. If no one had told me about active sound, I would not know it exists. Period. That'sall I have to say about that. What I CAN comment on is the sound of a good overtaking maneuver with the windows down and a rock wall beside the road. Pure motor sports! The snarl of the engine, the bark of the exhaust, and the clear and present rush of acceleration accurately communicate that sheep's clothing or not, this wolf is a force to be reckoned with and it will not be denied the right of way. (In Germany, that's really saying something!) It's worth mentioning that when you get too focussed on the sounds coming from the car, the 170 limit comes into play startlingly quickly, even during B road overtaking. Ooops.


In this rare case of EVO magazine and Top Gear actually agreeing on something, I will add my vote of confidence that BMW has accomplished something special with this version of the M5. If you drive one, you will not be disappointed.

Last edited by GTR-Dad; 06-18-2012 at 09:32 AM..
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