When you are using Zero Nitro Fuel, adding one percent Propylene oxide is a very good way to improve fuel/engine performance ...especially in cold weather. At low temperatures, methanol doesn't vaporize so well (low volatility). Adding 1% Propylene oxide to your fuel will improve starting and idling. Propylene oxide is extremely volatile, so it's best to add it to your fuel just before using the fuel. If you leave the cap off your fuel can, the Propylene oxide will soon be gone. It's best to buy it in small quantities and keep it cold... store it in your deep freezer.
http://www.dow.com/propyleneoxide/
Regards
JC