STA-BIL is a fuel additive that prevents the degradation that occurs in all types of petrol causing it to go stale. When fuel is stored, evaporation takes place over time, but the problem is that the many compounds that make up the fuels we use all evaporate at different rates which can significantly affect the combustibility of the fuel.

STA-BIL treats the fuel ensuring that the composition stays the same. Evaporation will still take place, but Sta-Bil ensures that the entire fuel compound evaporates at the same rate which means you shouldn't notice any difference between fresh fuel and treated fuel that may be several months old.