Star Tron is a unique multifunctional fuel additive that improves performance, and CURES Ethanol Problems. You will feel the difference from the first time you use it. Removes gum, varnish, rejuvenates stale fuel. Safe in all 2 and 4 stroke engines, cleans valves & injectors. Stabilizes fuel for 2 years. Helps prevent phase separation. 8 oz bottle treat up to 48 gallons of fuel. Overdosing Not Harmful.