This refers to the addition of acetone in petrol and diesel, and the potential action on any water within the fuel. For interest: https://www.physicsforums.com/threads/adding-acetone-to-the-gasoline.366946/ The above provides an interesting live understanding of the benefits to be gained...... however: This is primarily a question for chemists: Background: We are led to believe, that by adding acetone to fuel @ 1.5 - 2.5ml/L (diesel & petrol).... the fuel surface tension is reduced, allowing improved vaporisation, resulting in increased fuel burn efficiency. Note: my own practical tests have shown this to be the case. Idle speed immediately increased (ie. increased power output from combustion)...... and deposits on the spark plug reduced significantly (meaning better burn efficiency)....... many other independent tests produce similar results. There is no disputing, the improved fuel burn efficiency in both petrol and diesel engines. Question: How is the acetone mixing with the petroleum products? I have read that acetone 'combines' with water (possibly creating a gel-like substance). But this doesn't get to the fundamentals...... which are: We mix 2.5ml of acetone, with 1 litre of petrol, which has an additional 7.5ml of oil also mixed in. Within this mix.... theoretically, there may be the presence of water, due to condensation within the fuel reservoir. I'm questioning how is acetone mixing....... is it chemically combining with the petroleum products to produce the decrease in surface tension....... yet it can evaporate off....... and then..... what's the difference with water.... in effect....... is this a miscible scenario, or a chemical combination...... or in fact, what is actually happening?