Focus on model with 4x4 within the name
OC is a refreshed version of OB. You can see characteristics are the same.
One got offroad competitiveness to 232. The other one got 6.
Looking in details the car is appaling:
Even more strange, if I make a new trim and and activate modification, it instantly get back 179 competitiveness:
Same goes for the other OC version.
Even worse, if I edit the model, no change as any effect to competitiveness, for example here changing to semi-slick for an offroad (but it is the same no matter what):
so this looks like a bug.
To be even more clear, when I designed the new trim (OC models) in 1960, they all got better competitiveness than their older OB counterpart. So what happened in between?