Mobile vs. Fixed Fleet Wash: The Unit Economics Break Point
Every fleet manager running 50+ trucks, 100+ buses, or a significant rail car lease eventually asks the same question: do we build a fixed wash bay at our yard, or do we use a mobile fleet wash vendor? The sales pitches on both sides are strong. The right answer depends entirely on unit economics, and the break point is at a different fleet size than most people assume.
Here is the math, written for a Canadian fleet operator who wants to decide this honestly.
The Cost of a Fixed Wash Bay
Building a fixed wash bay at a fleet yard involves more than the equipment. The full-cost model:
Capital:
- Wash bay building or enclosure (heated in Canadian climate): $250-600k depending on size
- Water reclamation system and compliance with local sewer discharge rules: $80-180k
- Pumps, spray systems, brushes, undercarriage washers: $75-250k
- Electrical, plumbing, site preparation: $100-200k
- Environmental permits (varies by municipality): $5-25k
Total capital, typical medium-duty truck wash bay: $500k-$1.2M
Recurring:
- Labour — wash bay operator, typically 1 FTE per shift: $60-85k/year all-in per FTE
- Chemistry, supplies, wastewater treatment chemicals: $12-25k/year
- Utilities (water, heat, electric): $18-40k/year
- Maintenance on equipment: $15-35k/year
- Amortization of the capital over 10-15 year useful life: $40-100k/year equivalent
Total recurring, typical fixed bay running one shift, 5 days/week: $140-260k/year
The Cost of Mobile Fleet Wash
A mobile fleet wash vendor brings the equipment to your yard, washes the fleet on a scheduled cadence, and bills per wash or on a monthly flat. Typical pricing in the Canadian market:
Per-wash rates (typical 2026 Canadian pricing):
- Highway tractor: $40-65/wash
- Dry van trailer: $30-45/wash
- Reefer trailer: $45-75/wash
- Transit bus: $65-110/wash
- School bus: $35-55/wash
- Rail car (specialty): $120-350/wash depending on type
Volume discount tiers: 10-25% off at 50+ units/month, 20-35% off at 200+ units/month, negotiated pricing above 500+ units/month.
For a 100-truck fleet washed weekly (400 washes/month, 4,800/year), at an all-in negotiated rate of $40-50/wash: $195-240k/year.
For the same 100-truck fleet washed every 2 weeks (200 washes/month, 2,400/year): $100-125k/year.
The Break Point
The comparison:
| Scenario | Fixed bay annual cost | Mobile annual cost | Winner | |----------|----------------------|---------------------|--------| | 50 trucks, weekly wash | ~$180k | ~$120k | Mobile | | 100 trucks, weekly wash | ~$180k | ~$220k | Fixed (narrow) | | 100 trucks, bi-weekly wash | ~$180k | ~$115k | Mobile | | 200 trucks, weekly wash | ~$220k (add 2nd shift) | ~$400k | Fixed | | 200 trucks, bi-weekly wash | ~$200k | ~$210k | Toss-up | | 50 buses, daily school runs | ~$180k | ~$85k | Mobile | | 200 transit buses, 3x weekly | ~$250k (2 shifts) | ~$475k | Fixed |
The pattern: fixed wash bays dominate the economics at high volume with high frequency (200+ assets, 3x+ weekly wash cadence). Mobile dominates at low-to-moderate volume, flexible frequency, and when you value operational simplicity.
The middle of the range (100-200 assets, weekly wash) is close either way — which is where the decision comes down to non-economic factors.
The Non-Economic Factors
The unit economics are only part of the decision. The other factors:
Operational flexibility
Mobile vendors adjust cadence with your needs. Seasonal fleet operations, growth/contraction, route changes — mobile adapts. A fixed bay is sized for peak capacity and costs the same whether you use 60% or 100% of it.
Capital allocation
A $500k-$1.2M capital project competes with every other investment in your business. For a fleet operator deploying capital to tractors, trailers, or depot expansion, the wash bay is often the lowest-ROI line item. Mobile converts that capital into operating expense.
Labour management
Running a wash bay means hiring, training, and retaining wash operators. In most Canadian fleet markets, this is a high-turnover role. One full-time opening that takes 6 weeks to fill is a broken operation. Mobile vendors absorb that labour risk.
Environmental compliance
Wash water treatment and discharge compliance is getting harder. Municipal sewer bylaws are tightening on oil/grease content, heavy metals, and pollutant load. Building and maintaining a compliant fixed bay means owning the regulatory risk. Mobile vendors that manage their own reclaim and disposal take that risk off your balance sheet.
Geographic coverage
If your fleet operates from multiple yards, a fixed bay at one yard only serves that yard. Mobile can service multiple yards from the same vendor relationship. For multi-depot operators, mobile is usually decisive.
Cleaning quality consistency
A well-run fixed bay, with a trained operator, can achieve more consistent quality than a mobile vendor doing spot work. This is real — fixed bays do win on consistency when well-operated. But poorly-operated fixed bays (understaffed, undertrained) are worse than any mobile vendor. The variance matters.
When a Fixed Bay Is Almost Always Right
Three scenarios where a fixed bay makes sense despite the economics being close:
- Very high frequency wash requirement. Food-grade reefer fleets, cement trucks, refuse trucks — anything requiring daily or twice-daily wash. The per-wash mobile cost compounds.
- Controlled environment requirement. Specialized cleaning (food contact, haz-mat, medical) that requires a dedicated, controlled space. Mobile vendors cannot provide the controlled environment at your yard.
- Geographic isolation with no mobile provider. If your fleet operates from a remote location where mobile wash vendors are not available or pricing is inflated due to travel, self-perform makes sense.
When Mobile Is Almost Always Right
Four scenarios where mobile dominates:
- Fleet size under 100 assets. The fixed bay fixed costs are hard to justify.
- Multi-depot operation. Mobile vendors scale geography more cheaply than multiple fixed bays.
- Seasonal or variable demand. Fixed bays idle at 40-60% utilization still cost 90%+ of full operating cost. Mobile flexes with demand.
- Capital-constrained operations. Every dollar to wash bay is a dollar not going to income-producing assets.
The Hybrid Model
Some large fleet operators run a hybrid: a fixed bay at the highest-volume central yard, supplemented by mobile wash at satellite yards and for peak capacity. This is often the right answer for 300+ asset operations with multiple depots.
The key to a hybrid working: the fixed bay stays fully utilized (single shift minimum, often two), and the mobile vendor handles the volume above fixed-bay capacity plus the satellite yards. Rate-cards with the mobile vendor that reflect low-volume mobile economics (higher per-wash) are planned into the operating budget.
The Caravex Position
Caravex is a mobile fleet wash operator working with Canadian fleet operators, transit authorities, rail car lessors, and intermodal terminals. We are not the right answer for every fleet — operations with 300+ assets and daily wash cadence usually build fixed bays and run them well.
Where Caravex fits best: 50-200 asset operators, multi-depot operators, operators who value the operational simplicity of a single vendor relationship, and operators who are reluctant to put capital into wash infrastructure when the capital is needed for revenue-producing assets. Also rail car lessors where our yard-grade certification, environmental compliance, and specialty rail-car equipment are the right match.
If you are debating build-vs-mobile, the early conversation is worth having. Even if you decide to build, the conversation gives you a mobile cost benchmark to pressure-test the capital project ROI. Most of our longest-term client relationships started as "we're considering a wash bay; give us a 3-year mobile quote for comparison."