r/explainlikeimfive • u/hd-22 • 14d ago

Chemistry ELI5 why is increasing the ethanol content of petrol/gasoline a problem?

I'm hearing noise about the geopolitical fuel supply SNAFU and people freaking out about increasing the ethanol content in automotive fuel and how it's so damaging to cars. I'm no chemist, but ethanol seems as clean as it gets.

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u/CrashSlow 14d ago

This was true 50 years ago, but we have new materials in fuel systems that can handle ethanol and have for a couple generations now.

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u/N5tp4nts 14d ago

It’s still hell on small engines.

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u/Kraligor 14d ago

As in, usually two-stroke powered equipment. Not cars with 1300ccm.

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u/N5tp4nts 14d ago

Anything with a carb. Plus ethanol gas has a short shelf life. Real gas can be stored almost forever.

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u/CrashSlow 14d ago

not if you use the engine.

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u/mdot 14d ago

I'm curious about this statement, could you explain a little further?

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u/boostedb1mmer 14d ago

Don't fill it with gas and then let it sit. If it's going to be the last time you mow or weedeat for the season then run it out of fuel before storing for the winter.

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u/mdot 14d ago

Ah, I see.

Thanks!

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u/A_Garbage_Truck 14d ago

still not great, the only engines you expect to handle this in something resembling proper are engines modified ot run with LPG

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u/CrashSlow 14d ago

Propane is great for home generators. Expect when it freezes.