What throughput figures actually mean

Throughput is the first number anyone quotes for a wash system, and the easiest one to misread. Two machines can both claim a strong hourly figure and behave very differently once cars are queuing on a real site.

Operation time is not gate-to-gate time

A rollover figure quoted per vehicle usually describes operation time: the minutes the machine spends washing. It does not include the driver pulling in, straightening up, paying, or pulling away. On a busy day those in-between moments, not the wash program, are often what set the true pace of the queue.

Wash-only against wash and dry

Drying roughly halves what a rollover can move in an hour, because the machine spends a second pass on the same vehicle. A wash-only figure and a wash-and-dry figure from the same machine are both honest numbers; they are just answers to different questions. Ask which one a quoted figure describes.

Tunnels buy pace with length

A conveyor tunnel washes several vehicles at once as they travel through fixed stages, which is how tunnel figures reach well past what any rollover can do. The cost is footprint: the tunnel needs the length of the whole line, plus queue space at the entrance and room to exit cleanly.

When comparing systems, put the figures side by side on the same terms: operation time or full cycle, wash-only or with drying, and the site space each number assumes. The comparison is only real once the terms match.