The mysterious Lamborghini LP700-4 Aventador has finally been unveiled at the 2011 Geneva Motor Show. The “new 691-hp (SAE), 6.5-litre V12 engine out back – called “L539″ in Lambo-speak – is a massive 40 lbs.” Available in the US this October. Video after the break. Click here for more pictures.

To make this clear, the current estimated acceleration time for Aventador to 60 mph is 2.8 seconds (i.e. 2.9 to 100 km/h) when dallying in the fields of Launch Control. The engine howls with all power on tap now up to 8,250 rpm.

[via Autoblog]