2.2L V6 Turbo http://www.racer.com/lotus-confirms-indycar-v6-turbo-engine-to-be-built-by-judd/article/202716/
I've known John Judd for many years, a very talented engineer. i rate him and Brian Hart among the all time best.
No doubt. I've worked with a few teams who have used the V10 in LMP cars. A very stout motor indeed. The Ricardo gearboxes attached to the lump, however have a frequent tendency to puke on themselves.
Like others, I had assumed Lotus would work with Cosworth. Happy they aren't as it will allow the possibility for Cosworth to enter the engine side of IndyCar in the future. The more engine and aero kits available will be great for fans and the series.