Preventive maintenance (PM) intervals in mixed fleets must reflect how assets actually wear, not just how they are categorized. Choosing between hours-based and miles-based triggers directly affects uptime, compliance reliability, and long-term operating cost control.
| Asset Type | Primary Trigger | Secondary Trigger | Typical Range |
|---|---|---|---|
| Highway Trucks | Miles | Calendar | 8k–15k miles |
| Delivery Vans | Miles | Hours | 5k–10k miles |
| Construction Equipment | Hours | Calendar | 200–500 hours |
| Generators | Hours | Calendar | 150–300 hours |
| Utility Service Vehicles | Hours | Miles | 250–400 hours |
| Low-Use Specialty Units | Calendar | Hours | 6–12 months |
Mixed fleets combine assets that age differently even under similar operating environments. A single trigger method typically misrepresents true wear for at least one asset class. Dual-metric logic reduces blind spots and improves maintenance precision.
Outcome cues
Mileage is a strong indicator of wear when vehicles accumulate distance consistently and operate under similar duty cycles. It aligns well with tire wear, brake usage, and driveline stress.
Outcome cues
Engine hours better represent mechanical stress when assets idle frequently or operate equipment without covering distance. This is common in off-road or auxiliary-powered use cases.
Outcome cues
A unified framework blends miles, hours, and calendar time into one maintainable schedule structure. The goal is not complexity, but accuracy and repeatability across asset categories.
Outcome cues
PM intervals in mixed fleets are most effective when they reflect real utilization patterns rather than a single universal metric.
Preventative Maintenance Guide for Fleet Operations
How to Track Fleet Maintenance (Step-by-Step)
Preventive Maintenance Schedule Template
Fleet Preventive Maintenance Schedules