Diesel shops aren't gas shops
A diesel-focused shop runs on different economics than a typical gas-vehicle shop. Higher AROs ($800-$3,500 average vs $280-$450 for gas shops). Longer service intervals (15,000-25,000 miles between major services). More fleet customers and fewer retail. Specialty equipment that costs 5-10x what general shop tools cost.
The software stack reflects those differences. Or it should. Most diesel shops are running general auto shop software designed for 30-job-per-week gas shops, and quietly losing money to workflow misfit. Here's what actually fits.
What diesel shops need that gas shops don't
Fleet customer workflow. A diesel shop's revenue mix is often 40-70% fleet (B2B) instead of mostly retail. Fleet customers need PO numbers on every invoice, monthly billing instead of pay-at-pickup, and approval routing that goes through a fleet manager, not the driver. Most general shop SMS handles PO numbers and monthly billing as afterthoughts. Not as first-class workflows.
Longer-cycle service reminders. A daily-driver diesel might come in for an oil change every 15,000 miles instead of every 5,000. Service reminders pegged to gas-vehicle intervals miss diesel customers entirely. Your reminder system needs to handle vehicle-specific intervals, not category averages.
DOT inspection tracking. Class 6+ commercial vehicles need DOT-mandated annual inspections with specific record-keeping. Most general SMS treat this as another inspection type; a few handle it as a first-class workflow with reminders, expiration dates, and certificate generation.
Specialty parts ordering. Diesel parts often have longer lead times (3-7 days for certain engine components vs same-day for gas parts). Your parts ordering and customer communication need to handle "your truck will be down for a week" without breaking the relationship.
Higher-stakes diagnostics. Diesel diagnostics often run 2-4 hours of billable time before a repair quote. A flat $150 diagnostic fee model that works for gas shops doesn't work for diesel. The math forces shops to either eat 2 hours of labor or spend 30 minutes explaining the bill. Better software platforms handle tiered diagnostic fees natively.
The software stack for a diesel shop
The honest answer is similar to general indie shops, but with different priorities at each layer.
Operations / SMS layer:
- Tekmetric — handles fleet workflows decently, has DOT inspection support, modern UI. Best general-purpose pick for diesel shops in 2026.
- Shopmonkey — broader integration catalog, good fleet customer features, but priced higher than diesel shops typically need.
- Mitchell1 ManagerSE — still the most common diesel-shop SMS because of ProDemand's Heavy Duty database. If your diagnostic info is mostly Mitchell ProDemand, the integration depth is hard to beat.
- Mitchell1 Truck Series — Mitchell's heavy-truck-specific variant. Worth evaluating for shops 80%+ heavy-duty.
Retention / CRM layer:
- Pitlane — vehicle-aware CRM that handles diesel intervals, fleet customers, and B2B retention as natively as retail. Review automation, win-backs at 90/120/180 days, declined-work follow-up.
Fleet management:
- Fleetio or Whip Around for shops that want a dedicated fleet customer portal (PO submission, multi-vehicle tracking, monthly invoicing). Often runs alongside a shop SMS rather than replacing it.
Service info:
- Mitchell ProDemand with the Heavy Duty add-on, or ALLDATA for diesel-relevant repair info. ProDemand is more comprehensive on heavy duty.
Total monthly stack for a diesel shop running fleet customers: $500-$1,000/month. Higher than retail-only gas shops because the fleet-customer layer adds cost, but the AROs justify it.
Where the typical diesel shop loses money
Three quiet leaks:
1. Fleet customer reminder gaps. Fleets don't reach out when their trucks are due. They expect their shop to flag it. A diesel shop without a service-reminder system is leaving 15-30% of fleet revenue on the floor every year. (The math: 50 fleet vehicles × 0.5 missed services per year × $1,200 average ARO = $30,000/year in invisible losses.)
2. Underbilled diagnostic time. Without a tiered diagnostic-fee structure ($150 for first 90 minutes, $X/hr after), diesel shops eat thousands of dollars of unbilled labor every month on complex troubleshooting. Most general shop SMS don't handle tiered diagnostic fees natively, so shops either underbill or explain the bill awkwardly.
3. Slow approvals on big tickets. A $3,500 diesel repair waiting on fleet manager approval can sit for days. Shops without a tap-to-approve estimate workflow lose 1-2 days of bay time per delayed approval. At $500/day in lost capacity, that's $30k+/year for a 4-bay diesel shop.
What we'd recommend for an indie diesel shop in 2026
For a 3-4 bay diesel-focused shop doing $1.5M-$3M annual revenue with fleet customers:
- Tekmetric for operations ($229-$280/month) — covers RO workflow, DOT inspections, fleet PO handling
- Pitlane for retention ($197/month Growth tier) — fleet-customer service reminders, review automation, declined-work follow-up
- Mitchell ProDemand with Heavy Duty add-on for service info ($150-$250/month)
- Fleetio if your fleet revenue is 50%+ of total ($69-$150/month per fleet manager seat)
Total: $700-$950/month. Realistic for a shop doing $3M+ annual revenue.
What not to do
- Don't run a generic CRM (HubSpot, Zoho, Salesforce) with custom diesel workflows. The setup cost is real and the result is fragile. Use vehicle-aware shop tools.
- Don't pick the cheapest SMS just because diesel pricing is volume-driven. Workflow misfit at a diesel shop costs 5-10x what it costs at a gas shop because the AROs are higher.
- Don't skip the fleet portal if you have 5+ fleet customers. The PO workflow alone is worth $69-$150/month in advisor time saved.
How Pitlane handles diesel shop retention
Pitlane's vehicle-aware CRM treats diesel vehicles natively — VIN, mileage, service history, declined-work tracking. Service reminders are vehicle-specific, so a diesel customer due at 18,000 miles gets reminded at 18,000 miles, not at the gas-shop default of 5,000. Fleet customers can be tagged for B2B-specific message sequences (different cadence, PO-friendly language).