I changed my oil 1500 miles ago (one month ago) in my suv with quaker state and decided to run 1 quart of mmo in the oil. I ran sea foam and it did well, but my oil is extremely dark. (Oil is normally still golden blonde in color after 3000 miles ) in 500 miles I will change oil because of the color. I am satisfied because mmo is doing one or two things. It is either holding more contaminants in suspension, or it is cleaning out more crud from the depths of my engine. Either way I am satisfied. Who else has had this experience?