Yeah, in one of the recent auto rags, they said there was an Escalade running around with the pre-production 12. Said it moves the big SUV pretty well, and that it would be detuned to about 400 horses like kcnewell said, down from 500 or 600 from the concept engine.
I also heard something along those lines. I thought that I had heard that the V-12 is supposed to go into production and possibly into the XLR and the V-16 is to be a concept only engine. In order to better show off Caddy's impressive engine developement.
Let me say something about the "displacement on demand" engine.
I bought the 1981 Fleetwood BECAUSE of this feature. Back in the day it was called the V-864 and it was a technological marvel for its day. The engine would operate as a V8 at all times until cruising speeds were attained. As proper torques allowed, the valvetrain would shut the valves to 2 or 4 cylinders to save fuel.
I drove this car 330,000 miles without incident!!! Throughout this time I heard all sorts of bad press about this engine. The truth is that most people can not think for themselves... they will repeat any little thing they hear as fact. Somebody talked up Hondas and now there are millions of broken down Hondas on the road. The same people that bought those for the "great mileage" are now driving 12mpg SUV's... go figure... and don't even get me started about the minivans with the luggage on the roof
Anyway, even though the V864 was scrapped in favor of the HT4100 in 1982 (except in limos) the concept has been used in the Northstar engine for years now. This same technology is used to force open valves for air cooling of cylinders in the event of coolant loss.
The way that I am reading the current press is that the new V12 and V16 engine will run continuously on half of the cylinders and then activate the extra ones when called for.
That's exactly what they're supposed to do, Yes there were some problems with the 8-6-4 but overall they worked. with new technology the concept will work better and be more trouble free. My brother had one of the old ones and had very good luck with it and bought a '90 DeVille based on his good luck with his 8-6-4. I'll admit some folks weren't as lucky with them but some folks don't have very good maintenance practices either!
One of the things that I did to this car was to fabricate an override switch for the "variable displacement" system.
The system was programmed from the factory to only operate when the car was in high gear (3rd). This state was conveyed to the computer by means of a sensor mounted in the transmission. This was a simple 2 wire setup that supplied a ground signal when the transmission was in high gear. All I did was intercept one wire with a switch mounted on the dashboard. With this I could disable the system at any time forcing the engine to run on all 8 cylinders regardless of the situation.
I have to admit, it was a great thing to be staring at the fuel gauge on the interstate many miles from an exit and hit that sitch and watch the mileage sentinel jump from 20mpg to 32mpg instantly... whew!