There's a few threads and data about this but you'll just have to change the green more often. Our Toyotas have aluminum radiators and most greens don't have the same anti-corrosion properties needed that the Toyota red and pinks do. These 4Runners came with red initially but then Toyota developed their Pink LL (long life) fluid which supersedes red and lasts twice as long. Also won't corrode the radiators over time.
Royal Purple is a very good oil too. There's been a lot of lab tests on bearing wear and with AMSOIL absent (they rarely let anyone test it but themselves...) Royal Purple outperforms every other oil. Instead of cutting into the bearing, the Royal Purple oils create a sort of "smoothing" effect that actually polishes the bearing. No link though since it was in a magazine I read. I ran it a few times in my engine, didn't notice a difference of course since it's just oil but hoping the smoothing effect happened. I use their Max ATF synthetic in my transmission though, it works amazing. Cleaned up my 1-2 shift so it's crisper with less jerk. I modified my valve body to shift faster so it was so harsh it would make the whole dash shake before.
