BMW's EfficientDynamics teaser (2010)

This rather strange looking black BMW is the German car company’s latest publicity stunt. Painted matt black, and with ‘dontblogaboutthis’ emblazoned across its flanks, it is of course a tease designed to get forums fanatics and bloggers worked up into a frenzy as everyone tries to guess what it is. BMW has released just a few photos, plus a couple of videos, all of which are on www.dontblogaboutthis.com.

The basis of this media-savvy mule is the shell of the outgoing 6-series Coupe, but the nose has been heavily tweaked so that its resembles the EfficientDynamics supercar concept revealed at 2009’s Frankfurt motor show. It’s a step towards reducing both the cross-section and coefficient of drag, though the rest of the tall 6-series shell won’t make this prototype that efficient.

Like the EfficientDynamics concept, the modified Six also sits on very tall tyres. The reason? Fat tyres increase rolling resistance and fuel use, but taller, skinny tyres mean you can keep the same contact patch but radically cut the rolling resistance. Aero-optimised wheels help smooth the airflow too.

And if you’ve watched the video or looked closely at the pictures, you may have noticed that this 6-series runs silently, and that just one exhaust pipe pokes out the back. The ED concept ran a 1.5-litre turbodiesel mated to two electric motors, and this car no doubt runs a similar set up with a small capacity three-cylinder engine.

A BMW spokesman told us 'it's nothing official', but we hear that BMW is pushing ahead with creating a production version of its EfficientDynamics concept, and thus this car is just another piece in a PR puzzle as we build up to the launch in a few years time. And with the 2010 Paris motor show just around the corner, we wouldn't be surprised if there was another ED concept there, too.

By Ben Pulman