XRAY - Model racing cars

Why the maximum thickness of the oil increases (picked up suggestions Alex Hagberg - carpet):
T3 -> max 1000
T4 -> 1000-2000
T4'14 -> 2000-5000

Is it depends on the model or somethink else?

I have T3'12 and wonder about changing the oil from 2000 to 3000, because I quickly push the acceleration and push me a little

Must depend on model/track my 12 is on 2k any more and I found it looses too much steering when grip comes up on carpet.
I run 3k on my T2009 on low grip asphalt where I need a bit of push to control the rear.
Not run the 14 yet

Because over the years the electronics that we used have delivered more power for each year. Usually, the more power is used, the harder the gear diff is needed to give on-power steering and forward traction. Hence, in the stock classes, a bit lighter rear diff fluid is recommended.