Import Multi-Vehicle, Valvoline vs. Castrol, VI?

[Samzone]

I'm trying to decide between Castrol or Valvoline import multi to use in my 2006 Highlander with Aisin 3309/T-IV transmission. I used the Castrol in my Honda Element for 100K miles with zero problems. However, I noticed that the viscosity index for the Castrol is 200, where the Valvoline, a synthetic fluid, is closer to 150. This seems like a huge difference for two products that are essentially the same price. The question I have is, what is better in an ATF, higher or lower VI rating? For reference, the original Mobil 3309 fluid has a VI around 185.

 

[SatinSilver]

I'd go with the Castrol. It's closer to the viscosity of the oem fluid.

 

[slacktide_bitog]

My choice would be Maxlife

 

[michaelluscher]

I put Castrol IMV in my Camry's U151E

Biggest mistake ever

It slipped, flared, banged into gear,and just didn't behave like it should've

I think that 6 month 5k time it was in there took some time off its lifespan

I bit the bullet and ordered the case of Mobil 3309 off Amazon, and the second it went in, it worked perfectly

 

[53' Stude]

MaxLife is what's in my 11' Focus

 

[pbm]

I D&R'd the ATF in my s-I-l's 2004 Corolla with Castrol IMV @ approx. 140K. She wasn't sure if that was the original fluid but the IMV ran great and still looked cherry red when drained again 40K later. I recommend it in Toyota's that spec. 3309.

Maxlife has ran great in my daughter's Elantra that spec's SPIII.

 

[Samzone]

In looking at the Valvoline IMV and the Maxlife, I noticed that the Brookfield Viscosity (?) is quite different, IMV is 18000 and Maxlife is 10200. If Brookfield Viscosity means anything, then this is a significant difference, especially since these are both synthetic fluids from the same company. Any thoughts?