Let Me Know if You Have Allison Transmission Fluid Questions

A great thread. The 100,000 and 150,000 miles between changes recommended by Tom I assume requires fluid analysis to be sure it is ok to extend the change interval, right? Something I learned or was reminded of is to change my filter every two years even though the fluid is still good in my Allison 1000. I'll bite, what is the fluid that is $10 cheaper per gallon that can give 100,000 miles between changes?