I used Lubegard Engine Flush with reduce dosage in my cars. Instead of a full can (and more for 8.5 quarts sump E430), I used 1 oz per quart for 200-300 miles before oil change. Right now I use 1/2 oz per quart(3 oz in 6 quarts sump) in the newly purchased Volvo V70 with 140k miles for 500-600 miles then change oil and filter.