BMW's new aerodynamic test centre is reducing emissions and streamlining models, writes PADDY COMYN
AT THE risk of sounding cynical, you would have to wonder just how much CO2 BMW could have saved by just sending out a press release. But it seems the dreaded recession had by-passed Munich early last week.
In one corner of Munich airport, Porsche was launching a car so big, vast and inappropriate that it should be called Pan-Am, rather than Panamera; in the other, Australian, US, Canadian and even Thai journalists assembled, bleary-eyed from long flights, to learn just how BMW was shaving a couple of grams of CO2 off its next, large, executive car, the 5-Series GT.
It was like a UN meeting for motoring hacks, with different races, colours and creeds, all united in poor taste in clothes, protruding bellies and car-branded luggage.
BMW is proud of its EfficientDynamics initiative, as it should be. It has taken much of the guilt out of buying a new executive car and, in many cases, has made a mockery of our VRT system. It is fair to say that few within Leinster House banked on collecting just €156 per year in road tax from a 5-Series owner, but that’s the way it has gone.
All this has been done through some fuel-saving witchcraft which includes introducing Stop/Start technology that cuts off an engine when stopped, with the result that in Germany the average CO2 rating of BMW and Mini vehicles is 159g/km and there are 22 BMW models and seven Mini models with CO2 of less than 140g/km. From 2006 to 2008 alone, BMW’s average fuel consumption and CO2 ratings were down by 16 per cent, the average Mini rating by 20 per cent.
But far from patting themselves on the back and cracking open the Weiss beer, BMW designers have gone one step further and built themselves a new €130 million, 193,700 sq ft aerodynamic test centre – not one, but two big wind tunnels of which BMW is very, very proud. And rightly so.
BMW says that optimised aerodynamics have a direct impact on the car’s fuel economy and emissions and a 10 per cent reduction in air drag offers the customer a reduction in fuel consumption of more than 2.5 per cent.
To describe this facility, the only thing I could think of was Willie Wonka’s chocolate factory. Most surfaces are white, shiny and impossibly clean, the wind tunnel is made up of a turbine that looks like it came straight out of an A380 and brainy-looking German engineers stand behind a screen in a control room waiting to blow fast air at a car – very exciting.
You can tell a lot from a 300km/h, 71-tonne hairdryer. For a start, 40 per cent of the air resistance of a car is caused by its shape; 30 per cent by the wheels and wheel arches; another 20 per cent by its underneath; and the final 10 per cent by the air intakes.
If you could do without wheels, you would cut the coefficient of drag by 35 per cent. Sadly, BMW hasn’t figured out a viable alternative to wheels just yet. But this facility will ensure all new products coming from Munich will be smoother than Sean Connery.
And there’s more. Not only have they been busying themselves on the body, underneath, engineers have been locked away with orders to reduce tailpipe emissions without sacrificing power – the result is two new engines and a new automatic transmission. Replacing the 4-litre V8 engine is a new twinpower turbo six-cylinder. This 3-litre unit combines direct fuel injection, fully variable valve management and turbocharging and the result is 306bhp, 400Nm of torque and a fuel reduction of 9 per cent.
There is also a new diesel engine. The new straight-six diesel combines multi-stage more efficient turbocharging with common rail direct fuel injection and piezo injectors operating at 2,000 bar to make a mockery of the notion of diesels lacking in power. The new engine puts out 306bhp, more than 100bhp per litre and a staggering 600Nm of torque, yet there is a 4 per cent saving in fuel economy and emissions.
But to make these new engines even more miserly, they will add a new eight-speed automatic transmission. While this might sound like overkill, the more gears they add (up to a point) the more efficient the engines can be and the two additional gears give the transmission a broader range of increments and they have managed this while making the transmission lighter than the old one. It also helps reduce fuel consumption versus the former gearbox by 6 per cent.
The gearbox will debut on the 5-Series Gran Turismo, but will also feature on the 7-Series and is also all-set for hybrid and all-wheel drive models too. Stop/Start technology, previously only on manual transmissions looks set to become available for this 8-speed automatic at some point in the future, but it won’t be released at the first wave. No doubt some Australian journalists will need to be flown in for that CO2 saving measure too.
Factfile BMW’s 3-litre engines
PETROL
Capacity: 2,979 straight six with one twin-scroll turbocharger
Power: 306bhp, 400Nm torque @ 1,200rpm-5,000rpm
DIESEL
Capacity: 2,993 straight six, two exhaust turbochargers, two-stage turbocharging and small turbocharger
Power: 306bhp, 600Nm torque @ 1,500rpm