One 500 ml can is sufficient for up to 5 liters(1.3 gal.) of oil. Add Pro-Line Engine Flush to the engine oil at operating temperature before changing the oil. After adding the product allow the engine to idle for 10 to 15 minutes depending on the degree of contamination. Then change the oil and the filter. Pro-Line Engine Flush is compatible with most commercially available engine oils, and in oil running belt. Minimum oil filling of 3 liters(0.8 gal.) is requested for optimum product performance.Observe: Not suitable for use on motorbikes with wet clutches.