Something cheaper is the 2 stroke oil in 1 gallon blue jugs at Walmart. Even in my 2006 Jetta, I gain 10% mileage when I added it. I have not in a while, was kind of a pain. I need to get a bunch of little bottles and fill them all at the same time then just dump in when filling. I put it in my Excursion as well, but it is too difficult to track mileage when it is rarely driven without a trailer behind it.