River rat did a lot of work and fine job, but even then I was skeptical. Gravity flow in pans etc isn't oil flowing under pressure. Then there is Amsoil, where everything they show, theirs is at the top it seems. The Toyota media seems pretty thick, it looks good at least, and the design simple and effective. Looks the same as the cartridge media to me. When I use them, my oil seems to stay pretty "golden" like the expensive filters. I don't think there is any downside to using a Toyota part on a Toyota. I wish they did have some more tests of current Denso filters so there is at least one more data point.