I just tryed a new fuel in my saito 180. My standard fuel is wildcat 20%nitro/20%synthetic oil. My engine produced about 9400 rpms with a 17x8 prop. I changed to a 10%nitro/20% oil sig fuel(50%castor/50%synthetic). I lost about 300 rpms but the engine runs noticably cooler. For what its worth, I don't know if its the castor or the reduction in nitro that alows it to run cooler. The needle setting range was much wider with the 20%nitro.