I purchased a gallon of Cool Power 15% total synthetic glow fuel the other day for my NexSTAR Select. I was told by a coworker yesterday that I shouldn't run 15% and I should not run total synthetic fuel. He said I should run a combination of castor and synthetic because synthetic burns all the oil and leaves the engine dry with no oil on it and causes rust and corrosion. He says the castor provides lubrication for the engine because it doesn't all burn. Is this true? Did I make a mistake purchasing and using this fuel?