Probably this has already been discussed here but I can´t find where.
Next oil change in my gearbox GM 5, I plan to replace the oil by the Dexron VI
What are the pros and cons to replace the Dexron III for the Dexron VI?

Cheers

Dexron VI supersedes Dexron III i.e. it’s backwards compatible.

On paper Dexron VI has a lower viscosity, which could be significant if your valve block assembly is worn and therefore leakage could increase. In reality though, Dexron VI is more resilient/stable and its viscosity will not reduce over time as much as Dexron III did.

Phil

So Phil,

Your advice is that I can use Dexrom VI instead of Dexron III.
I Own the RR TD6 for about one year. I've change the oil on the gearbox and I intend to replace it when it makes 25.000 Kms +-.
I intend also to add a bottle of Lucas transmision fix just to prevention,
Am I correct?
Thank you and best regards