I thought I saw graphics during the Japanese GP that Kimi's engine was doing close to 20K.....though exactly how close those audio-based analysis can get to the accurate rev of the motor is not known to me...
I saw something in autosport, apparently they are already close.
Murphy's 9th Law of Technology:
Tell a man there are 300 million stars in the universe and he'll believe you. Tell him a bench has wet paint on it and he'll have to touch to be sure.
It's nice to have them make that final step of development, even though they will not be able to use it in F1 next. Well the people are employed so they better develop the engine as long as possible before cosworth cut some of their working staff.
You might consider it a statement for any team that needs an engine in 2008 or later then