BMW has announced it will sell 1.5 million 3- and 4-cylinder engines by 2015.

It’s all part of the premium giant’s intention to become even more green, and continue its EfficientDynamics drive.

It’s also a staggering number: last year, BMW sold 1.5 million cars IN TOTAL. It wants to drive this to 2 million by 2015 – meaning 3 in 4 of them are to be, well, 3 or 4 cylinder units.

Which finally means its famous HQ has come into its own.

See, for years, BMW has been famous for 6-cylinder engines. Its straight-sixes have long been adorable, with icons including most of the 1970s and 80s mainstream stuff, plus the 325i, the 528i, the E46 M3, the E34 M5, and umpteen more besides (what I wouldn’t do for an E36 328i Touring, for instance).

Since the E36 318i started becoming the company car of choice in the 1990s though, 4-cylinders have started to win out.

Good. I love BMW 4-cylinder engines, for their raspy goodness and throbby involvement: since diesels started to become good in the E46 too, they’ve joined the pile for offering thrusting power and amazing economy.

Which takes us to the Munich HQ. Built between 1968 and 1972, just in time for the 1972 Olympic Games, it’s known as BMW-Vierzylinder in German. Yes, ‘BMW four-cylinder’. Although most prefer simply ‘BMW Tower’. The Karl Schwanzer-designed building won historical status in 1999, and is said to be the most iconic piece of architecture in Munich.

UK fame

It first really came to the UK’s attention with the Rover fallout (remember the late-night reports on the news when the crisis was unfolding?). How strange, said car commentators at the time, that a brand famed for its 6 cylinder engines should live within an HQ paying homage to the 4-cylinder engine.

Not anymore. 4 cylinder units already give BMW its profitable volume, and it looks this is set to continue in the future. Indeed, the 4 cylinder look like they’re going to supplant 6-pots, with 3-cylinder units nipping in below the 4-pots. See the new X3 xDrive28i’s 2.0 TwinPower twin-scroll turbo as the first step towards this.

BMW is cutting its cylinder count, improving its economy, not affecting its engine power and, yes, making its famous HQ fully relevant in the modern world.

Architects are clever folks, and have to go to University for 7 years to qualify. But I didn’t know just how clever, until this.

The future of the BMW car predicted by the architect firm that designed its HQ? Well, I’ll be…

+ Customer feedback steers BMW engineers

+ Profiling the roads of the world with BMW

+ BMW April Fool brilliance (once again)

BMW’s latest 5 Series marks the introduction of 4-cylinder engines into the F10 platform. Until now, it’s been all 6-cylinders or V8s.

Powertrain manager Jan Kretschmer revealed what’s been keeping them busy at the launch of the 520d variant, on the debut of this September’s F11 Touring.

My, they’ve been well-occupied, it seems. ‘4 cylinder engines are always a bigger challenge for our engineers,’ he explained; even ones like this, with counter-rotating balancer shafts.

They have, as you know, a different (‘and higher’) level of NVH – noise, vibration, harshness. ‘You have to consider this before you even start with the development and installation.

‘Luckily, our Body-In-White department is able to conduct a lot of simulation work (big investment in computer technology over the past half-decade facilitates this). This means we can predefine possible weaknesses where extra stiffening may help – or, actually, stiff areas where some weakness may be beneficial!

‘They start this 5 years before the vehicle hits the road.’

Concurrently, his powertrain team will be working to provide the smoothest possible engine for eventual implementation. With the 184hp (135kW) 2.0-litre diesel, Kretschmer explained the process was one of evolution. ‘We were tasked with further refining an already high-level engine, rather than reinventing it.’

Two key development areas were prioritised here:

•    Engine Mountings: ‘These must be isolated. We fit electronically driven semi-hydraulic engine mounts, with 2 characteristics. At idle and low rpm, they are ‘weaker’, to absorb low-level vibration. When driving, there are fewer engine vibrations, so we stiffen them to improve handling.’

•    Fluctuating Torque: ‘This is harder to isolate on 4-cylinder engines than 6-cylinders. On manual models, we fit a pendulum-type flywheel which minimises these oscillations and reduces the booming rear axle effect. The 8-speed auto has a new torque converter with a twin-damper system that provides isolation.’

Minimisation of fluctuating torque is the aspect he is most proud of, as it is extremely significant. ‘We have reduced it going into the transmission by 60 percent.

‘This helps us drive the car more at lower rpm, with longer gear ratios on the manual and new gearshift profiles on the auto. With the new 8-speed, this alone has led to a 9 percent improvement in fuel efficiency!’

in doing so, Kretschmer has created a ‘5-litre’ engine for the 5 Series (that’s 5 litres per 100km – 56.5mpg). Don’t think his efforts have gone unnoticed by the Board, either.

‘This is the volume model for the 5 Series, so the pressure has been on us to further improve.’ Good job, really, that he’s done just that.

+ Do you think BMW makes the best 4-cylinder engines on the market?
+ Would you consider a 520d?
+ If not, what are the main reasons stopping you chosing diesel?

HOW do you make a MINI One engine? Make a MINI Cooper engine and detune it. Simples.

It’s true, as well. All 1.6-litre MINI engines, be they in the First, the One or the Cooper, are now exactly the same. They’re built on the same line and have all the same bits inside.

A MINI engineer from UK build centre Hams Hall told me this is for production efficiency. By standardising all the parts, it actually works out cheaper than having bespoke variations for each version.

So, although a MINI First engine may thus seem more ‘valuable’ than a Cooper engine, it’s actually much more efficient for MINI and all its buyers alike to do it this way.

Besides, the intelligence is in the ECU mapping, anyway. Releasing the power in the Cooper is more than just switching a different number or two in a computer. That’s where your extra Cooper value comes in – knowing brains have been boffing-ing away in giving you the extra value, but in a driveable and linear way. You’re buying into someone’s IP.

It’s the two other versions that really benefit, though. See, the old MINI First and One had 1.4-litre engines. ‘People complained they lacked torque – with the 1.6-litre, we’ve filled in the gaps, but the longer gear ratios also mean it’s more efficient, too.’

Does beg one obvious question, though. How long will it be before Superchips-like companies offer a Cooper-creating First tuning kit for the MINI?

There’ll be distinct Porsche crossovers if they do: back-to-basics Cooper Club Sport, anyone?

+ MINI is not the only firm doing this – can you name any others?
+ How does MINI’s approach contrast with the downsizing trend?
+ Could future MINIs move back to smaller engines with turbo to fill the torque hole?

CITROEN wants to become Europe’s third-largest brand.

No, I’m not sure how, either. Right now, it’s seventh-largest.

Sixth? Its partner, Peugeot. So, a right old odd statement for new chief Jean-Marc Gales to make, then. I’m still puzzling over it. But what also caught my eye in the Automotive News interview he gave was another revelation.

That Citroen doesn’t need to produce 6 or 7 million cars to survive and thrive. Because, instead, it enjoys economies of scale from compnents alliances with other car makers. Meaning it can make big-number money on smaller-number car production.

Take engines. Citroen co-operates with Ford and BMW on them. Which, Gales tells Automotive News, are the most expensive parts to develop in a car. Pair up, share the costs with a partner or two, and that’s a whole heap of cash you don’t have to claw back in higher-volume efficiencies of scale.

But yet something else grabbed my attention in what he said. Engines remain the most expensive bit of all, aye? Well, I’ll be.

Explains a lot, mind. Why the VW TDI is omnipresent. Why car makers are so willing to sign up to co-opt deals. Why the Ford 1.25-litre Zetec is a decade and a half old.

And why electric or fuel cell cars can’t be that far away, surely.

Yes, they’re expensive. But if developing tomorrow’s combustion engines is also heinously dear, won’t car makers soon consider designing a new generation of IC engines to be economically unviable?

Car brands always look to the future. And, Lord knows, it ain’t in fossil-fuel-hungry ICs. Developing a new range to meet, say, 2012/2015 emissions legislation won’t be easy. Or cheap.

Whether Citroen will indeed be in the EU Top 3 by then is, of course, another matter entirely.

bmwblog and UK car dealer agree

Image of the week: 4 April 2009

Fuel economy economical with the truth?