How to buy a car wash (and check the numbers before you do)
Short answer
To buy a car wash, start with the type (express tunnel, in-bay automatic, self-serve or full service), then verify car counts by day from the controller or POS, membership (unlimited wash plan) revenue and churn, and average revenue per car. Test those against independent records: water and sewer bills, chemical purchases and card processor deposits. Then price the equipment, the land or ground lease, and the capex coming due.
Membership revenue is the most valuable part and the most important to verify.
Car washes combine retail, equipment and real estate. Each part has its own traps, and weather makes the numbers swing month to month. The good news: modern washes generate a lot of independent data.
How a car wash makes money
| Type | Revenue driver | Key metric |
|---|---|---|
| Express exterior tunnel | Volume and memberships | Cars per day, member count, revenue per car |
| In-bay automatic (often with a gas station) | Single washes, fuel bundles | Washes per day, average ticket |
| Self-serve bays | Coins, cards, time used | Revenue per bay |
| Full service / detail | Labor-intensive packages | Ticket, labor % |
Cross-check the volume
- Controller and POS data: cars by day and package for 24+ months.
- Card processor statements and deposits: card sales should match. See proof of cash.
- Water and sewer bills: usage should track car counts, adjusted for any reclaim system.
- Chemical purchases: soap, wax and other chemicals scale with cars washed. Supplier invoices are independent.
- Membership system: active members by month, cancellations, failed card payments.
Worked example: test car counts against the water bill
Every car through a tunnel uses water, and the utility meters it independently. If you know roughly how much fresh water the wash uses per car (ask the seller and the equipment supplier, and check it against the reclaim system's specs), the water bill tells you how many cars were really washed.
Illustrative example, not a real wash or equipment spec
The controller reports 96,000 cars last year. The equipment supplier says this tunnel, with its reclaim system, uses about 15 gallons of fresh water per car. That implies 96,000 × 15 = 1,440,000 gallons. Water bills show 1,560,000 gallons for the year. The extra 120,000 gallons (about 8%) could be leaks, landscaping, bathrooms or a reclaim system not working well: worth asking about, but consistent with the car count. If the bills showed 900,000 gallons, the wash either uses much less water than claimed or washed far fewer cars. Do the same test with chemical purchases: soap and wax use per car is fairly stable for a given package mix.
Memberships: the most valuable line, and the easiest to dress up
Unlimited wash plans turn a weather-driven business into a subscription. That's why buyers pay attention to them, and why sellers sometimes run aggressive promotions before listing. Ask for active members at each month-end for 24 months, new sign-ups, cancellations and failed payments, and the price each member pays. A burst of members on a first-month discount that later cancel will show up as churn after you close. Members are billed by recurring card or bank payments; ask your attorney whether the authorizations and billing setup carry over, and check your state's automatic renewal rules, since some require specific disclosures and easy cancellation.
Equipment and real estate
An express tunnel is a long machine: conveyor, brushes, arches, dryers, pumps, controller and the water reclaim system. Get the install date and service history for each major component, and have an independent equipment technician inspect it. Many sales include the land; if so, the SBA lender will appraise the real estate separately, and the SBA 504 program or a 7(a) loan with a real estate portion may apply. SBA's September 2026 technical update to SOP 50 10 8.1 also allows a single change-of-ownership loan to amortize beyond 10 years, up to 25, when it includes owner-occupied special purpose property whose value depends on the business; ask your lender whether your wash qualifies. If the land is leased, the ground lease term and rent escalations matter as much as anything on the P&L. Wastewater is regulated: ask for sewer or discharge permits, grit trap cleaning records and any notices from the utility. If you're buying the land, a Phase I environmental site assessment is the usual first step.
Add-back traps
- Owner as maintenance tech. Tunnels break; someone has to fix conveyors and pumps at 7am on Saturday. Price a technician or service contract.
- Deferred equipment replacement. Brushes, dryers, controllers and conveyors have finite lives. See deferred maintenance.
- Weather. A dry, dirty year flatters results; average several years.
- Membership promotions that boosted member counts just before listing at prices that won't hold.
Worked example: what a rainy month does
Illustrative example, not a real wash
A tunnel has 2,400 members paying $25 a month ($60,000) and sells single washes averaging $14. In a normal month it sells 4,500 single washes ($63,000). In a rainy month, say singles fall by 40% to 2,700 ($37,800) while member revenue stays at $60,000 because members pay whether or not they wash. Revenue drops from $123,000 to $97,800, a 20% fall, instead of 40%. A wash with no members would see the full 40% fall. That's the practical reason memberships matter, and why you should look at the worst months in the history, not the average.
What moves the value of a car wash
We don't value deals or publish multiples we can't verify. Appraisers and lenders weigh these factors:
| Factor | Supports a higher value | Pulls it lower |
|---|---|---|
| Membership base | Large, stable, at full price | Promotional members, high churn |
| Site | Visible, easy access, owned or long ground lease | Poor access, short lease |
| Equipment | Newer, serviced, with reclaim | Aging tunnel, deferred replacements |
| Competition | No new tunnels nearby | New express washes opening |
| Records | Controller, POS, water and chemicals all agree | Gaps between them |
Questions to ask the seller
- How many active members did you have at each month-end for two years, and at what prices?
- When was each major piece of tunnel equipment installed, and what's due for replacement?
- Who fixes breakdowns, and how long was the wash down last year?
- Any new car washes planned or under construction nearby?
- Any notices from the water or sewer utility?
- Is the land included, and if not, how long is left on the ground lease?
The first 90 days after you buy
Keep the wash running exactly as it does now, especially membership billing and the wash packages members are used to. Line up an equipment technician you can call at 7am on a Saturday, and stock the parts that fail most often. Track cars by day and package, membership adds and cancellations, and water and chemical use per car from the first week; those numbers will tell you quickly whether something is wrong with the equipment or the market. Membership marketing and package changes come after you've seen a full month of your own data.
Documents to request
- Tax returns, P&Ls, bank and processor statements (3 years).
- Controller/POS reports by day and package; membership reports.
- Water, sewer, electric and gas bills; chemical supplier invoices.
- Equipment list with install dates; service records.
- Deed or ground lease; site plan; zoning and permits; any environmental reports.
- Staff list and pay.
If real estate is included, the SBA lender will appraise it separately from the business, and the real estate portion can carry a longer term. See SBA 7(a) for acquisitions.
Frequently asked questions
How do I verify car wash revenue?
Export car counts and sales by wash package from the tunnel controller or POS, reconcile card sales to processor statements and bank deposits, and compare volume with water usage and chemical purchases over the same months.
Why do memberships matter so much?
Monthly unlimited plans create recurring revenue that's less weather-dependent. Check active members by month, churn, and how many members wash so often that they're unprofitable.
Is the land included?
Often, because car washes are real-estate-heavy. If it's leased, the ground lease term and rent are critical. Real estate is appraised separately from the business in SBA deals.
What environmental issues apply?
Wastewater discharge, water reclamation systems, and chemical storage are regulated locally and by state agencies. Ask for permits and inspection records.
How do I check whether car wash members are profitable?
Divide each month's membership revenue by the number of member washes that month to get revenue per member wash, and compare it with the single-wash price and your cost per car (water, chemicals, power, labor, wear). Members who wash several times a week can cost more than they pay; a healthy plan has most members washing a few times a month.
What does a car wash's equipment cost to keep running?
It depends on the tunnel and its age, so get the service records and an independent technician's inspection rather than relying on the seller's estimate. Ask what was replaced in the last three years, what the supplier recommends replacing next, and what downtime cost on the busiest days. Treat a realistic annual replacement budget as a cost when you look at earnings.
Sources
- SBA SOP 50 10 8.1, Appendix 15 (real estate appraised separately; blended terms)
- IRS: About Form 1099-K
- EPA: NPDES permits (wastewater discharge)
- EPA WaterSense
- CFPB Regulation E, 12 CFR Part 1005 (recurring electronic payments)
- ASTM E1527-21 (Phase I environmental site assessment)
- SBA 504 loans
Related guides
General information, not legal, tax, financial or investment advice. Rules and lender practices change; check the linked sources and talk to your attorney, CPA and lender about your deal. Examples with named numbers are illustrations, not real businesses. OKtoBuy's Deal Check does not value businesses or give price opinions.