ive had a quart of trinity monsterhorsepower 20% in a dresser type drawer for like almost 2 yrs and it still worked great. as long as u sqeeze out the extra air in the container and cap it tight and keep it out of sunlight and the temp stays consisentent it will last awhile-and u can use old fuel to clean a nitro engine or degum one-i saw an articile in a mag about what to do w/ old fuel