... we recommend you can drive on the low-grade for the initial stage, then improve slowly, about 15 days ... the best.After installation, keep no moving for 8 hours, then drive for about 1 hour to reach the fuel ... dirt carbon, after driving 800 km later or other machine turn on 15-20 days, these phenomena will disappear ... packing:11,more product detail: China high quality powerful magnetic fuel saver for car