Sound right to me. The other three numbers that can be clearly seen following the N45.0 (20.0, 40.0, and 10.0) are for the vehicle decay times.
20 would be Enemy expire time, for when the enemy takes the vehicle spawned and abandons it,
40 for Field expire time, when a friendly abandons the vehicle in the field, and
10 is for Decay time, when an unmanned vehicle is sitting on a control pad that has been captured by the enemy. It may also be for when a friendly vehicle is abandoned within an enemy command post's control region, but I am not sure of that.
Keep the spawn time above the decay time or you could crash the game or at least have stacked vehicles.