Viewing a single comment thread. View all comments

MisterSquidInc t1_ja6docu wrote

Reply to comment by ECatPlay in If the fuel that goes in car engines is extracted from hydrocarbons, which consist of only Hydrogen and Carbon, and those hydrocarbons react with Oxygen in the air (combustion reaction), to produce CO2 and H2O, why do we get a bad smell from car exhaust fumes if both gases are odorless? by Protoflare

I've noticed when running E85 (in this case race fuel, so guaranteed 85% ethanol) the exhaust has a sweet, almost fruity smell to it.

Do you know what causes that?

7

murderhalfchub t1_ja7mqjt wrote

My guess would be incomplete oxidation of the ethanol to aldehydes. Aldehydes are responsible for fruity smells like grape, banana, apple, etc. But this is a guess.

Source: studied chemical engineering in college and took organic chem

7