:confused:
Just to add one more opinion to the mix, but I thought (and was fairly sure until I read the above) that mechanical breakdown was not simulated. Previously, it had been called "outside the scope of CM", i.e. the mechanical breakdowns would change the number of tanks that you had available for the battle, but CMBO/BB was not going to model breakdowns during the battle.
IIRC, the ground pressure value, plus terrain and movement speed, are the only influences on bogging, and the vehicles do not have an extra rating for mechanical reliability.
However, having said all that, I don't have the manual in front of me, so this is only my opinion, and I'm quite willing to be corrected. Does anybody have a quote from the manual, or an old thread that would settle this?