My DZ likes the cool power Heli fuel 30% nitro i dont need the power on the H 9 Taylor craft but it runs very consistent with the Heli fuel that is what YS performance and Central Hobbies is now recommening for the DZ the oil viscosity in the Heli fuels is thinner and flows better. Mine isnt broke in yet but Chad who is a Ys expert says the biggest difference also is the fact you only need to have high end needle out 1 to 1and 1/2 out . The first 140DZ i had did break a crankshaft right after 2 gallons of fuel but it was a rare deal. Central Hobbies sent me a new motor no questions asked .