I did my first oil change on my recently acquired 2004 Chevy Venture. My mileage on a 700 mile road trip came in at 26.9 miles per US gallon (8.74 liters per 100 km). (This was 90% moderate highway driving.) I can't find my "before the oil change" mileage, but I think it was 5 - 10% less. With the amount of driving I do, I should save $300.00 to $400.00 in a year. Are those of you that use synthetic oil seeing similar results?