Can You Really Use Coca-Cola To Dissolve Rust On Your Car? – SlashGear

In the technical sense, the answer is yes: Coke can clean rust off of a car’s metallic surfaces. Just as it does with the grody penny, Coke’s phosphoric acids loosen the bonds between rust and the metal beneath, allowing you to scrub it right off.

Here’s the problem: remember how that penny needed to be completely submerged in a glass of Coke for several minutes before the oxidation started coming off? It’s the same with car rust. To clean rust off your car with Coke, you’d need to completely cover the spot with Coke and keep it that way for a potentially very long time, much longer than it would take to clean rust in traditional ways. If you’re performing a little spot clean that only requires a thimble’s worth of Coke and a few minutes, that’s perhaps workable, but if the rusty patches are especially large, you’d need to remove the metal part from your car completely, and drop it in an entire kiddie pool full of Coke for potentially several days. For regular cleaning purposes, it’s obviously less than ideal.

It’s also worth noting that Coke can leave a crusty sugar residue on your car after cleaning with it, which can attract bugs. Additionally, the phosphoric and citric acids in Coke can strip away the finish from your car’s paint job if left too long, not unlike the enamel of your teeth. Metal is tough, but it’s not invincible.