Use it to break in new engines, if you are worried about the oil content just add some Castor. If it will run at all it is good enough for break in as you can control the situtation and don't care how it preforms in flight.
I inherited two gallons of Tower Hobbies 4 stroke fuel, found out it was 15% nitro 18% oil, add a little castor and it would be fine for breaking in engines.