Can fuel additive still be used after one year of expiration?

[OOscar]

Fuel additive can be used normally if it has not expired for a long time. However, if the expiration period is too long, such as half a year or one year, even if used, it will not achieve the effect of cleaning carbon deposits. The internal additives' physical and chemical properties may degrade or become unstable, potentially causing damage to the vehicle. Therefore, it is not recommended to use it. The role of fuel additive: The main function of fuel additive is to increase the octane number of gasoline, making it burn more completely and reducing the formation of carbon deposits. This helps maintain the engine's power and fuel consumption, preventing a decrease in engine power and an increase in fuel consumption due to excessive carbon deposits. How to use fuel additive: Add the fuel additive to an empty fuel tank, then add gasoline. Typically, 60ml can be mixed with 30-60 liters of gasoline. If the fuel tank capacity is more than 60 liters, two bottles of fuel additive are needed, but do not overuse it.

[VonMaddox]

I saw the question asking whether fuel additive can still be used after being expired for a year. Honestly, I wouldn't recommend it. Having maintained my car for several years, I know that additives degrade over time—chemicals can precipitate or change form, potentially clogging fuel injectors or the pump and increasing engine wear. Their effectiveness plummets too; cleaning power is basically gone, making it a waste of gasoline money. Best to check the bottle's date and safely dispose of expired products—don’t risk costly repairs to save a few bucks. Get into the habit of regularly clearing out car supplies, like checking antifreeze and additives every three months, to avoid stockpiling forgotten items. This way, you'll drive with peace of mind and save money.

[Clifford]

I've been driving for over a decade and used many fuel additives. Avoid using ones that expired a year ago as their components become unstable over time, prone to deterioration and separation. Using them results in poor cleaning performance and may leave residues damaging the engine—more loss than gain. I remember once using a near-expiry product to save money, which caused unstable idle speed—later diagnosed as an additive issue. Now I've learned: check expiration dates before buying, purchase only what's needed, and use promptly for peace of mind. Experience shows negligence in small things leads to costly major repairs—regular maintenance is simpler. Vehicle upkeep relies on daily care; don't let expired products complicate matters.

[EstherMarie]

Don't use expired fuel additives anymore. If it's been expired for a year, it's definitely unusable. Over time, the product deteriorates, and pouring it into the fuel tank could clog the fuel lines and affect the engine. The effectiveness is long gone, so it's just a waste of effort. Check the label to confirm the expiration date and dispose of it safely. Preventing small issues is much better than repairing major faults.