One, two, or three tires?

A common metric in the wheel-washing world is tires, as in, “You probably need a one-, two-, or three-tire system.” That refers to the number of revolutions the tire makes; i.e., a one-tire system cleans a vehicle’s tires in one full rotation. For a semi-truck tire (a common measure), that’s about 11 feet of travel.

“If you’re washing off light soils, you need a one-tire system,” says Waystack. “Heavy clay soils require a three-tire system. Most landfills require a two- or three-tire system. Facilities washing off magnesium chloride usually want a two-tire system. You want to get that stuff off quickly and thoroughly to prevent rust.”

Water pressure and volume

Another decision specifiers must make concerns the amount of water used and at what pressure. Two philosophies prevail:

  • High-pressure systems that use low volumes of water
  • Moderate-pressure systems that use more water.

Neptune’s systems are almost always designed to use moderate pressure and higher volumes. “We think they’re better because they’re easier on equipment,” Waystack says. “Higher pressure systems can save water, but they can also potentially damage seals, electrical components, and brakes. With moderate pressure, you get everything clean without damaging the vehicles.”

Next page: Drive-through versus roller