Not so much for mileage, the effect is observed in sub-freezing temperatures, as much as reduced wear. Oil testing has shown the transmission oil in the NHW20 is good for about 60k miles and the NHW11 about 30k miles. However, I'm running a test using the NHW20 oil in an NHW11 to see how it works out.
I'm also running a test series on the ZVW30. Data indicates an early change at 5k miles may be key to getting longer service life out of the oil. The analysis revealed unexpected particulate material and sealant in the oil. I'll know when I change the oil at 20k miles and get the test results.
Bob Wilson