so what exactly is the 25,000 1/yr guarantee mean? What are they guaranteeing? I know amsoil makes excellent products, but their SS0 oil is states a service life of 35,000 miles or a year, or severe of 17,500. I really have not seen any uoa with that type of mileage on a normal vehicle. The higher uoa tend to show that it is a very good oil, but sometimes I wonder what they base their claims off of.