When should fuel additive be added?

[VonJohnny]

Add before refueling. This allows the fuel additive to fully mix with the gasoline under the impact of subsequent gasoline injection, achieving optimal usage results. Additional Information: 1. Fuel additives are primarily composed of nano-molecules, cleaning activators, antioxidants, anti-corrosion agents, demulsifiers, and over ten other components. They are specifically designed to target harmful substances in fuel such as sulfur, gum deposits, and engine carbon buildup, thereby enhancing power, promoting combustion, providing anti-oxidation, anti-wear, cleaning, dispersing, demulsifying, anti-corrosion, and lubrication effects. 2. The main function of fuel additives is to clean carbon deposits, which has always been their key selling point. Additionally, they help maintain the engine and fuel system. Certain specialized fuel additives can also improve the fuel's anti-knock properties (octane rating).

[MacCody]

I usually add the fuel additive to the tank before refueling, so that the gasoline can disperse it more evenly when filling up later. I remember during my last maintenance at the 4S店, the technician told me it's best to add it before refueling—pour in one bottle and then fill up the tank. Don't just add it randomly; you need to check the maintenance manual because different cars have different requirements. For my American car, it's recommended to add it every 5,000 kilometers, while for Japanese cars, it's suggested to add a small half-bottle with every tank of fuel. If the car runs on highways frequently, you should add it around every 3,500 kilometers; otherwise, severe carbon buildup can cause idle shaking. Never add it when the tank is almost empty—the concentration would be too high and could damage the fuel system.

[CorbinRose]

My habit is to add fuel additive every time before refueling when the fuel light comes on, as this is the safest approach. After adding the fuel additive, you must refuel immediately; otherwise, the excessive concentration may corrode the fuel pump's sealing ring. It's best to start using it after the break-in period for new cars, while for older cars, the effect is most noticeable after using it continuously for three full tanks of fuel. Once, I tried to save time by adding half a bottle to half a tank of fuel, and the engine malfunction indicator light came on. Now, I always follow the instructions by adding a whole bottle and then filling up with at least 40 liters of fuel. Remember, the effect of fuel additive is more noticeable in turbocharged cars, while naturally aspirated engines may not show any noticeable difference.

[DeTessa]

I usually pour the whole bottle of fuel additive into the tank before refueling. It's best to add it when the fuel level is down to 1/4, then go refuel immediately. When I first bought the car, I didn't know better—once I remembered to add the fuel additive only after refueling, and it settled at the bottom of the tank for a week before mixing properly. Pay attention to the shelf life of fuel additives; use them within six months after opening, or they'll oxidize and lose effectiveness. Add cleaning-type additives before highway driving, while maintenance-type ones can be added during regular use.