Quote Originally Posted by Transporter View Post
When the petrol containing even small amount of ethanol comes in contact with water of any form, liquid or just as humidity the ethanol will absorb it and once it reaches a saturation point, the ethanol and water will phase separate - forming 2 or 3 layers in the tank. So, you will have an upper layer of petrol, than layer of ethanol and water or the worst (it's also common) a third layer of water only. The consequences of that are often catastrophic for the engine.

The ethanol is a very aggressive solvent and will attack gaskets, O-rings and rubber hoses. Those who don't use their cars every day are even worst of, since the deterioration is the worst while the car is standing (you go on holiday or otherwise don't use the car for a few weeks).
The fuel system components made of certain type of plastics will become soft or hard and brittle, brass, aluminium and copper will oxidise to the point of failure.

It's okay to use the ethanol in the racing cars, because the racing car engines very often need to last only the length of the race plus one more lap.
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