Does adding fuel additive harm the car?
3 Answers
Adding qualified fuel additive does no harm to the car. The functions and usage methods of fuel additive are as follows: Functions of fuel additive: Its main function is to clean carbon deposits, which has always been its product selling point. Additionally, it helps maintain the engine and fuel system. Some special-purpose fuel additives can also improve the anti-knock performance (octane number) of fuel. Usage methods of fuel additive: The usage method of fuel additive is very simple—just pour it directly into the car's fuel tank to mix with gasoline. The best time to add fuel additive is before refueling: add the fuel additive first, then add gasoline.
I've been in auto repair for over a decade, and car owners often ask if fuel additives harm engines. It depends on usage. Legitimate PEA or PIBA-based cleaning additives are actually quite safe—like giving your engine a spa treatment. But steer clear of those small workshop products that recklessly add manganese salts while claiming to boost power. Manganese deposits can ruin spark plugs and oxygen sensors. Also, avoid fuel additives labeled as 'octane boosters'—they're pure scams and may actually cause engine knocking. The worst case I've seen was someone using three bottles of subpar fuel additive consecutively, which completely clogged the catalytic converter, costing over 8,000 yuan in repairs. So stick to reputable brands and follow the recommended usage frequency—they're genuinely effective for cleaning carbon deposits in direct injection engines, but don't count on them for fuel savings.
Last time I heard Old Zhang next door saying he always adds fuel additives when refueling, I couldn't help but worry for him. His old Jetta has already clocked 200,000 kilometers, yet he still uses polyetheramine fuel additives as if it were a brand-new car, resulting in severe piston top coking. Fuel additives should be chosen according to the vehicle type. Direct injection engines benefit from polyetheramine additives to clean injector carbon deposits, but excessive use in port fuel injection engines can actually contaminate the engine oil. During my repairs, I've disassembled many fuel systems - properly maintained vehicles do have clean intake valve backs, but engines abused with inferior additives have oil pans full of gummy deposits. Most importantly, never trust the no-name products gas station attendants push - some fuel additives contain alarmingly high alcohol content that even swells rubber fuel hoses. For new car owners, I'd advise against randomly adding any additives before the first maintenance service.
