Depends on how much water. A small amount of water and the engine will run better when warm, this has been known for years. (in 1915 some engines came with the factory with a separate carburetor just for adding water) It doesn't work if there is any ethanol in the fuel though, so almost nobody does it. The biggest downside is it needs a warm engine, if the engine is not warm it just runs bad, and in the worst cases it won't even start.

[–] gravitas_deficiency@sh.itjust.works 3 points 1 day ago (1 children)

You’re talking about water injection, which is very, very different from having water in your fuel lines, which will make the car not run at all. Water has a higher specific density than gasoline, and will settle to the bottom of the tank, which is where the fuel pump pickups are located. And an internal combustion engine cannot combust water because it’s… water.

[–] bluGill@fedia.io 2 points 1 day ago

Water and gasoline do mix just fine in small amounts. When the car is moving it shakes enough to mix a little more. This is small amounts though, they may be mixing more water than that.

Other reports suggest this isn't a case of mixing water, but instead a low grade gasoline that shouldn't be used in engines because of ocatane.

[–] Skua@kbin.earth 3 points 1 day ago (1 children)

Wouldn't water increase octane rating, since higher octane fuel is harder to ignite wth compression and water wouldn't ignite at all?

[–] bluGill@fedia.io 1 points 1 day ago (1 children)

I don't know what that tool measures but I wouldn't be surprised if it didn't account for water correctly.

Though since then I've read reports that this is not water but just bad gasoline.

[–] Skua@kbin.earth 1 points 1 day ago

My personal guess elsewhere in this thread was diesel, since it does have an extremely low octane number compared to gasoline and it would be easy for Russia's infrastructure to supply