Jack it some worlds it does make sense! Thanks for that lond detailed explaination!
I guess you just have to play with that squish # untill you get it right!
What are you comparing the Gryphon to? The speedo?
I am running LT tires would that mean they are less squishy? Therefore less of a % (eg. 1-2) making Squishy 8-9%
The calculation in the user manual does not account for the squishy?
( I just like uing the word squishy! )
W/O the squishy I calculate manually 285/55R20: 2581mm

I guess this will have to be my starting point!