An apparatus and system, preferably mounted on a service vehicle, provides synchronized application of fluid materials, either solid or liquid, to a vehicle travel surface in proportional amounts or spatially distributed proportions in response to user defined requirements andor operation of a vehicle mounted component in response to conditions encountered in real time. A wire positioning rib is formed on the cover member and is brought into contact with the wire to position the wire. Each blade has an average throat angle defined by the cosine arc of the ratio between the average throat length at mid-height of the blade and the circumferential pitch evaluated at the radius of the average throat point; the average throat angle ranges from 57\xb0 to 60\xb0.