This depends on the state of your vehicle's engine. If your engine's injectors are heavily contaminated with carbon deposits, your valves stick and are also widely contaminated with carbon deposits, you could notice the effects right away. If your engine is already clean, you can keep it clean by using ARDINA fuel additives and prevent problems. In addition, if you use our premium products such as the Diesel Detox Pro or the Gasoline Detox Pro, you also get other benefits as well.