Does Gasoline Cause Metal to Rust Compared to Water?

AI Thread Summary
The discussion centers on the corrosion resistance of metallic fuel injection tubes and gasoline tanks compared to water. It highlights that gasoline, being a hydrocarbon, does not rust like iron does, as rusting is an oxidation process that requires oxygen. However, the presence of air above gasoline in tanks can lead to oxidation if water condenses and mixes with the gasoline, particularly in older steel tanks, which can rust internally when water accumulates. Newer ethanol-based fuels help mitigate this issue by dissolving water, reducing rust formation. Fuel injection rails are often made from aluminum, which does not rust like steel but may require anodizing for compatibility with ethanol fuels like E85. Overall, while gasoline itself does not cause rust, the interaction with water and oxygen can lead to corrosion in metal components.
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If yes how about in comparison to water? I ask cause I was wondering how they stop the metallic fuel injection tubes from rusting out. Is there a coating or does it just not rust in presence of gasoline?

Im assuming that gasoline doesn't rust since its a hydrocarbon and water contains O, and rusting is the product of oxidation. Is this correct?
 
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Well, I'm not sure, but keep in mind that gas tanks in automobiles, for example, often have a substantial area above the gasoline that common air sits.
Through condensation and other factors, the water and oxygen(and other gases) in that air is mixed to some degree with the gasoline.
 
Your question is not as simple as you think. "Rust" is a generic term for oxidation that generally refers to Iron Oxide. The same sort of oxidation reaction can occur with other metals. Water doesn't cause rust, but it's presence does facilitate the process of rust formation on Iron. I doubt that automotive fuel lines are made of Iron, or even of mild steel, for that matter. As for steel gasoline tanks; examine a very old one and you will discover that they do, indeed rust.
 
a metal cannot "rust" without oxygen. but i can corrode..im guessing there is a coating on the inside of the tube.
 
After working with old cars for many years I have found that steel tanks don't rust (internally) unless they get water in them (which they all do) that is with conventional gasolines/petrols where the water and petrol do not mix, in this case the water sinks to the bottom of the tank and causes it to rust in that location. Newer ethanol based fuels dissolve the water in petrol and reduce the rusting effect.
 
They'll rust, same as brake lines, from the inside out usually.
Fuel rails that are on the engine, aluminum I personally have on my car, are simply that, aluminum. I am thinking about running E85 on this car, and also about this being an issue, they'd possibly have to be anodized inside.
 
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