It's time again for a transmission fluid flush on my 2004 Corolla with 321K miles. I've always used synthetic tranny fluid rated for T-IV applications. To save money, I'm thinking about switching to Valvoline MaxLife ATF (on sale at AutoZone for $17.99/gallon). From what I understand, Valvoline MaxLife ATF is a lower viscosity fluid, for use in WS applications, but it reads on the bottle that it can be used for T-IV applications.
I'm hesitant, because wasn't the Gen 9 Corolla built to use the higher viscosity T-IV and wouldn't a lower viscosity fluid not provide the protection it needs? Or......is it backwards compatible and it's perfectly fine to use a lower viscosity tranny fluid in a T-IV application? I know that the reverse is not the case: You can't or shouldn't use T-IV higher-vis fluid in a car built for low-vis WS fluid.
Thanks for any replies.
I'm hesitant, because wasn't the Gen 9 Corolla built to use the higher viscosity T-IV and wouldn't a lower viscosity fluid not provide the protection it needs? Or......is it backwards compatible and it's perfectly fine to use a lower viscosity tranny fluid in a T-IV application? I know that the reverse is not the case: You can't or shouldn't use T-IV higher-vis fluid in a car built for low-vis WS fluid.
Thanks for any replies.
