You have to use the type F due to compatability reasons. If you were to completely remove all residue from the Polaris oil (dis-assemble & wash off parts) Dextron MIGHT be OK to use. However, it can react with the oil left in the hub, and cause all kinds of problems. One guy I know got a used machine, and the hubs weren't working properly. The fluid in the hubs was red (we assumed it was Dextron) and there were 'clumps' in the oil. It required a COMPLETE disassembly of both hubs, new seals, and parts washing, to get the hubs working again. I can't prove the wrong oil caused this, but I wouldn't take the risk.