After mounting the automotive magnets in my motor-home, I had reported that the mileage had increased from 9 km. per liter of diesel fuel, to 11 km./liter. But, I remembered reading that the fuel efficiency should increase after several tankfuls, as the impurities should be flushed away. So, now about five tankfuls later, I am excited to tell you that the mileage went up to 12.5 km./liter! Quite frankly, I believe that this should be impossible to achieve with the size, shape and weight of my motor-home, but Eureka, it has happened! A million thanks to Mundi Magnets! Regards,