Does Gasoline Cause Metal to Rust Compared to Water?

Click For Summary

Discussion Overview

The discussion centers around the effects of gasoline and water on the rusting of metals, particularly in the context of automotive fuel systems. Participants explore the mechanisms of corrosion, the role of oxygen, and the materials used in fuel lines and tanks.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants propose that gasoline does not cause rust due to its hydrocarbon nature, while water, containing oxygen, facilitates oxidation.
  • Others argue that the presence of air above gasoline in tanks introduces water and oxygen, which may contribute to corrosion.
  • A participant notes that "rust" typically refers to iron oxide and that other metals can undergo similar oxidation processes.
  • It is suggested that automotive fuel lines are not made of iron or mild steel, which may influence their susceptibility to rust.
  • One participant shares observations that steel tanks do not rust internally unless water is present, particularly in conventional gasoline, while newer ethanol-based fuels may mitigate rusting.
  • Another participant mentions that aluminum fuel rails do not rust in the same manner and raises concerns about using E85 fuel, suggesting the need for anodization.

Areas of Agreement / Disagreement

Participants express differing views on the conditions under which rusting occurs, particularly regarding the role of water and the materials used in fuel systems. No consensus is reached on the overall impact of gasoline versus water on rusting.

Contextual Notes

Participants highlight the complexity of corrosion processes and the specific conditions under which rusting occurs, including the presence of water and the materials involved. There are unresolved assumptions about the definitions of rust and corrosion.

Who May Find This Useful

This discussion may be of interest to automotive enthusiasts, materials scientists, and individuals concerned with corrosion in fuel systems.

Qaiphyx
Messages
92
Reaction score
0
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?
 
Last edited:
Engineering news on Phys.org
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.
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
5K
Replies
8
Views
4K
Replies
12
Views
6K
Replies
4
Views
3K
  • · Replies 3 ·
Replies
3
Views
16K
Replies
1
Views
6K
  • · Replies 27 ·
Replies
27
Views
4K
Replies
14
Views
6K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 9 ·
Replies
9
Views
5K