According to Amsoil, if you use their oil filters along with their oil, you can run it for 25k (less under severe use). So...I ordered an oil filter, too. I figured that the oil is just about the same cost as Castrol Syntec, and the oil filter is a few bucks more than a K&N oil filter or another premium filter. Add on shipping and it's about the same or a few bucks more. So...realistically speaking, I'll probably change the oil 2x a year instead of 4 or 5x. That still saves me money and hassle. And NOW that I know that it's a MLM thing, maybe I'll look around a little more next oil change...