Movement bias has been "plus'd up" by half again in this case. The units have 50% more movement points than they normally would.
Dismount means if the unit moves into terrain where the vehicles can't go, the vehicles get returned to the replacement pool and the infantry proceeds without them. From one of the pages on the Matrix site.
1. Dismount Feature:
This new feature is intended to allow motorized infantry to shed motorized transport and thus become foot infantry – allowing it to enter and conduct combat into locations barred to motorized units by certain terrain (dunes, badlands, etc.).
The feature is accessed via the Unit Report. After the “Transport” pane, there is a check box to effect the dismount IF the unit contains any motorized transport. Upon clicking, the motorized transport is removed from the unit (sent to the “On Hand” pools). Then the unit may have “Foot Movement”. While it will only have the foot movement allowance, as a foot unit, it could then operate in dunes and etc.
After dismounting, the Inventory Report will reflect the increase in transport numbers according to the amount released from the unit.
The option to dismount remains available even if the unit is unsupplied. But, if you effect that option, you will first be given a warning. But, if you go ahead and effect the dismount, the motorized transport is not sent to the “On Hand” pools. Rather, it is sent to the dead pile.
In order to resume motorized movement, the unit must first be restored to “mounted” status. To do so, click the Dismount check box back to off. Then, the unit will start to receive motorized transport as replacements in subsequent inter-turn phases. If the box is left in “dismounted” status, no such replacements will be received (leaving the unit in foot mode). But, once unchecked, it will receive them.
If the unit contains Static equipment (towed artillery mostly), then if the transport in the unit had been removed while the artillery remained, the unit would have been switched to a MP of 1 – not what was intended. So, this feature also removes any Static equipment as well.
To enable players to keep track of which units have been dismounted or can be dismounted, the “OOB – Units” Report now has a column to reflect that.
Note that there can be instances where a unit consists entirely of motorized transport and/or Static equipment. In that case, dismounting the unit will have the same effect as disbanding it.
If sub-units have been dismounted then recombination will only result in a dismounted parent if all sub-units were dismounted.
While the primary purpose of the feature is to allow motorized infantry to temporarily operate as foot infantry, other uses can be imagined. For example, it might be used to protect trucks from unnecessary losses in combat by dismounting just prior to combat execution.
It could also be used by designers to model a mostly foot army with some, short term, trucking ability. All infantry could have trucks in their TO&E, but then all be dismounted. Then, if there was only a small amount of trucks available in the pools, an occasional unit could mount-up for a swift transfer to another area, then return the trucks back to the pools by dismounting.