Have been using SIG fuel since I got my plane (4 gallons through it). I got this stuff off of my instructor. He had it from when they order fuel in January. I'm out now and the closest thing I can find is Omega. Same nitro content, same oil content, and same syn/castor ratio. Will it hurt my engine to switch brands? The manual says it will leave carbon deposits. So is it o.k. to use or not?

Fuel is SIG 10% nitro, 20% oil (50/50)