What size car wash is most profitable?

Express tunnel sizing

Tunnel length determines how many sequential cleaning, soaping, drying, and finishing steps you can run on a single car. Common ranges:

• Under 100 ft — limited capacity for differentiated upsell tiers. Often the format choice for in-bay tunnel hybrids or limited-footprint sites. Lower capex but lower ticket capacity.
• 100–130 ft — entry-level express tunnel. Supports 3–4 wash tiers but ticket compression versus longer tunnels.
• 130–180 ft — the sweet spot. Supports 4–6 differentiated wash tiers, allowing operators to anchor at $12 base and reach $25 premium. Throughput remains strong at 80–120 cars/hour at peak.
• 180–220 ft — premium format. Supports full menu including ceramic coating and tire shine. Throughput slows slightly; capex increases meaningfully.
• Over 220 ft — rarely justified. Diminishing returns on capex and throughput.

Site-level sizing constraints

Tunnel length is not always a free choice. Site geometry, lot size, and zoning often constrain practical length to a range. The recommendation: choose the longest tunnel your site supports up to 180 ft, then optimize within that.

Full service and detail shop sizing

For full-service operations, building footprint matters more than tunnel length. 8,000–12,000 sq ft supports a viable full-service operation with interior detail bays. Detail shops can run efficiently at 4,000–6,000 sq ft with 4–8 work bays.