i have my Private pilots licence . and well KEROSEINE** ( jet-a ) av gas is used for turbine motors\ certain turbo prop[s , however im not sure they mix it in with the standard av gas you buy from the pumps at the airport. Av gas and altitude will effect the way the aircraft runs . The higher you go , the lower the compression will get . Therefore that is why airplanes run higher octane gas, it provides the engine with more BOOOOOOOOOOOM for your BUCK , to keep you in the air ... The higher you go , the lower the atmospheric pressure is , for every 3000 feet its considerd 1 atmospheric pressure less *** , As the altitude is increased, the air pressure becomes less, and the density, or pounds of air per cubic foot, becomes less. If the engine is to maintain its rated horsepower at increased altitudes, it must take a much larger volume of air from the atmosphere surrounding it, in order to keep the weight flow from decreasing. I dont know exactly how this corrosponds to a banshee because you are not climbing and decending 3000+ feet at a time , however this is just some knowledge i wanted to share with you all ...... Try flying a cessna 172 at 12 thousand feet with some 93 pump gas... Youll be lucky if u can get the engine to even stay on .