What's the difference between C30P and C30R ?
The airframe it fits in?
C30P 206 L1 (retro) thru L4
C30R/3 OH58D with a kind of Electronic governor?
Civil
here
Military
here
Knock yourself out!
All small turbines will always use a lot of fuel. Even supposedly modern engines have similar SFC to the old 250 series. Problem is in the tip clearance of such a small engine relative to its size. Yes you could improve it but at what cost and for how long?
As the engines get bigger they have a better SFC but it tends to be reflected in the price. Check out a GE T700/CT7 SFC.