BMW's EfficientDynamics

You'd think times like these might be pretty grave for a company like BMW. Here, after all, is the outfit that markets its product as "the ultimate driving machine", on the promise of a muscular engine on a sharp chassis. And while the Germans have never lived by crude old bore-and-stroke methods of boosting performance alone (fuel's long been too pricey for that in Europe) BMW has been known to go pretty big -- 6.0 litre V12s, for example -- to fulfil that.

So the path it's taken of late is perhaps not surprising. Yes, they're working with hybrid technology -- it will make its first appearance in 2009 in a version of the X6. But they've simultaneously come out in defiant defence of the standalone internal combustion engine. Not only are performance and fuel economy not at odds, they declare -- they're entirely compatible. Efficiency is efficiency, and true efficiency does not benefit one party at the expense of another.

And perhaps not surprisingly either in a business world obsessed with formularised branding and strategy, they're spreading the word through a branded strategy.

Which is why, if you've read anything about BMW in the last year, you've probably come across something called EfficientDynamics.

EfficientDynamics: the essential whats and whys
EfficientDynamics is, in a nutshell, a survival strategy. When you've invested more than half a century and billions of deutschmark developing a product aimed at maximising driving pleasure (and put your major shareholders near the top of the global rich list in the process), you're not about to junk it all just because fuel supplies are dwindling, demand is rising and Al Gore and co are accusing your industry of ruining the environment.

EfficientDynamics is BMW's response to rapid change in social, environmental, political, and economic conditions. They're rolling it out in three phases...

So what does EfficientDynamics mean for us, here, now?
For now, EfficientDynamics is BMW's way of bridging the gap between old imperatives (read: performance, fun) and new ones (read: fuel economy, cleanliness). In other words, reducing fuel consumption and CO2 emissions while simultaneously improving performance.

The basic tenets of this phase include smaller, force-fed engines, new fuel processing and energy management systems, reductions in weight, friction and rolling resistance and aerodynamic improvements.

Which, in concert, have spawned a whole bunch of new things happening between that signature double kidney grille and that badge on the bootlid. Things that all add up, the company claims, to cars that are better in every way.

Smaller petrol engines with turbocharging to make more of less
Force feeding has never sat well with engineering traditionalists and purists. Certainly BMW's boffins have historically seen the continuous refinement of fundamentals as the key to a quality drive, without recourse to bolt-ons like turbocharging.

Not any more. BMW now sees the blower -- twin blowers, actually -- as an important means of extracting similar or better performance figures from smaller engines. So they've taken to it with gusto. And in so doing they've been able to chop 1600 thirsty cubes and four cylinders from their top-end product. Goodbye six-litre V12 760Li. Hello twin-blown 4.4 litre V8 750Li. With, they say, much better fuel consumption figures and virtually no sacrifice in performance (300kW, down from 327, but the same 600Nm of torque). Indeed it accelerates faster.

It also means BMW spotters have to relearn the language of the bootlid badge. In the old days, the badge denoted the model series and the engine capacity. So '750' meant 7-Series with a 5.0 litre mill, '528' meant 5-Series with a 2.8 litre six and so on. Now, '750' means '740 with same engine but turbocharged', '135i' means '125i with same engine but turbocharged'. This no doubt helps their production efficiencies -- the few engine basics they're making, the better for them, consumers and the environment.

Nano-accurate fuel injection to make even more of even less
They're also fitting those engines with a high-precision fuel injection system. Using electro-active piezo crystals, suffice to say it's bloody complicated. But it works by squirting a smaller than normal cloud of fuel spray through a thinner than normal needle (about a hair's breadth thick) at a higher than normal pressure, closer than normal to the spark. Because none of the fuel goes unburned in the cylinder, none goes wasted. Sensors monitor the changing demands made on the engine moment to moment and adjust the spray accordingly. It all adds up to a bigger bang, every bang, from less fuel. Which ultimately means more bangs per litre.

Turning the diesel into a lean, green athlete
This, too, happens care of turbocharging, long the standard in giving oilers the low-end kick they need to reach an urban speed limit in less than an afternoon. BMW calls its Variable Twin Turbo system "another quantum leap in diesel engineering". Maybe, maybe not. But it's as close as anyone's ever come to closing the performance gap between diesel and petrol engines.

The system combines a small and a large blower running individually or together, depending on the demands being placed on the engine. This is not just a parallel or sequential system -- it's more complex. It starts at low revs with just the small one. Midrange it calls in the big one, but only to force-feed the small one to boost its pressure. At high revs, the small one hands the whole job over to the big one.

The result: performance hikes of up to 25 per cent with instant, lag-free responses low down and kilowatt figures to match similar sized petrol engines (alongside the normal diesel blessing of prodigious torque). BMW claims the 3.0-litre, 180kW 330d hits 100km/h in a blistering 6.2 seconds.

All with emissions fulfilling stringent Euro 4 standards and unfeasible parsimony -- BMW quotes 6.8L/100km combined cycle for the 330d.

Energy management: making the most of all those kilowatts
An engine is an energy converter. It turns the potential energy contained in fuel first into heat energy and then into kinetic energy with which it shifts you from A to B. But as it does that, it has all sorts of other devices riding piggyback as well. It's recharging the battery and powering lights, radios and electric windows/mirrors/seats/etc via the alternator, and activating all manner of pumps and compressors for the cooling system, power steering and brakes and air conditioning.

This is conventionally done by mechanical means, for example using belts connecting the alternator and the air compressor to a drive wheel off the end of the crankshaft. And there's a whole bunch of hydraulics to run as well, for brakes and steering. Every one of these syphons energy from the engine, running as they do at full capacity from start till stop.

Well they did, until the advent of what BMW terms "need-based operation of ancillary components". That means replacing mechanical coolant pumps and hydraulic power steering boxes with electric ones, activated by sensors that turn them on only when they're needed. And air-conditioning compressors with magnetic clutches that disconnect completely when the air's switched off.

How effective is this? Here's just one example: BMW claims its electric coolant pump consumes up to 90 per cent less energy than its mechanical counterparts.

Brake energy regeneration
One of the chief freeloaders among all those ancillary components is the alternator -- that normally belt-driven generator that recharges the battery and powers electrical components when the car is running. BMW has come up with alternator that activates only during power-off times, when you take your foot off the accelerator or hit the brakes. So it helps you decelerate, then gets out of the way when you need your engine power back. All of it. At least until a sensor detects an alarming drop in battery charge and activates the alternator to top it up.

BMW claims this element alone boosts fuel efficiency by up to three per cent.

Auto start-stop
Bring the car to a complete halt, for example at traffic lights, put it in neutral and the car switches the engine into a kind of sleep mode. Put it back in gear, put your foot down and the engine restarts instantly, as if you'd been idling all along.

And it's smart enough to know when and when not to do it. It won't make start-stop available until the engine has reached optimum running temperature. And it won't restart the engine if it detects undone belts in occupied seats or open doors, bonnet or bootlid.

But it automatically restarts the engine if it detects the car starting to roll, or if the battery charge drops too low -- even when it notices the windscreen starting to fog up.

Reductions in weight, friction and rolling resistance
They've long pounced on every opportunity to reduce engine weight. In 1994 they were first to market with the all-aluminium crankcase. This generation of engines is all-aluminium, full stop, and up to 20kg lighter than the ones it supercedes. They're turning to carbon fibre, too, at least in their premium models, the best known example of its use being in the roof in the M3 coupe.

To cut energy-sapping component friction, they've gone for a special light transmission oil and installed a thermal management system that warms up the final drive, helping cut frictional resistance more quickly after starting the car.

Plus they've stiffened up the side walls on this fleet's tyres with special heat-resistant materials designed to reduce distortion under weight. This minimises rolling resistance, producing a smoother ride, better fuel efficiency and reduced emissions.

Aerodynamic improvements
An open grille is one of the aerodynamic weak points in any vehicle. But a high-efficiency engine doesn't need a constant flow of air through the grille to keep it cool. So BMW has installed sensor-activated, electrically powered flaps on the air inlets that open only when the engine needs air. They say this cuts air resistance enough to have a palpable effect on fuel consumption.

A swag of awards
So far, the people of carworld like what they see. The diesel-powered 118d took out the 2008 World Green Car of the Year prize, and the company has garnered green awards from journals around the world, including from the highly regarded Car and What Car? in the UK, and countless home-turf magazine awards.

They also like it to be known they've drawn plenty of plaudits from independent, non-partisan, non-hoon sources. Like the scientific advisory council of the ECO Trend Institute, for their work on emission reduction, the use of recyclable materials and eco-conscious production methods.

Perhaps part of the reason for its success is that little of this is new beyond the name. The US Environmental Defense Report, an independent study of the fuel consumption of all new cars sold in the US between 1990 and 2005, gave BMW top billing among manufacturers for its contribution in cutting fuel consumption and CO2 emissions.

EfficientDynamics has also won the company the nod three times running on the Dow Jones Sustainability Index as the 'world's most sustainable car maker'.

But none of that mattered in the shadow of the headline: Prius 17.2mpg, BMW 19.4mpg ('Prius 16.4L/100km, BMW 14.5L/100km' just doesn't have the same ring to it...).

There are people in Detroit who'd happily give a kneecap for that kind of press.