Strangely enough, both Castrol ATF's have an unusually high viscosity of 8 cSt @ 100°C and 36.6 cSt @ 40°C.
Valvoline's Max Life "Suitable for use in Toyota Type T-IV applications" ATF is considerably lower than expected at 6.11 cSt @ 100°C and 26.16 cSt @ 40°C, and actually "Exceeds the latest performance requirements of DEXRON®-VI and MERCON LV® fluids" which have a relatively light viscosity.
Toyota's #08886-01705 partially synthetic T-IV ATF is likely made by Mitasu in Japan, which has a normal viscosity of 7.3 and 38.86 cSt.
Mobil's 3309 ATF is at 7.2 and 35 cSt, Amsoil at 7.5 and 38.8 cSt, and Redline at 7.5 and 34 cSt... If I was stuck with a godforsaken automatic, I think I'd go with Mobll Super (Canada's version) Multi-Vehicle ATF (7.42/34.1 cSt, 193 VI), only surpassed by Redline's 198 VI.
http://www.castrol.com/liveassets/bp...eage_06812.pdf
http://www.valvoline.com/pdf/maxlife_atf.pdf
http://jaytec-lubricants.com/index.p...=images/Toyota
http://www.mitasuoil.com/en/multi-vehicle-atf
http://www.mobil.com/USA-English/Lub..._ATF_3309.aspx
http://www.mobil.ca/Canada-English-L...icle-atf.aspx#