While breaking in your engine, and until you get some experience with correctly tuning the engine, it is a good idea to use a fuel that contains at least some castor oil. It provides superior engine protection against damage from running with an excessively lean air/fuel mixture. Once you become familiar with tuning, fuels with a higher percentage of synthetic oil may appeal to you becuase of the reduced gooey residue.

If you buy an OS engine, or a Thunder Tiger engine, they will both work quite nicely with fuels that contain zero nitro, & also up to as much as 15% nitro. For general sport flying, anything past 10% nitro is wasted money.

Get the Thunder Tiger.