How should a small fleet schedule preventive maintenance?

This is general information, not legal advice. Check the rules in your province or state.

Should you use the maker's schedule or a fleet-wide rule?

The maker's schedule. The best starting point for a small fleet of cars, SUVs, pickups and vans is the maintenance schedule the manufacturer wrote for each vehicle. It already covers the engine, transmission, fluids and filters that vehicle has, and it usually comes in two versions:

• a normal schedule, and
• a severe-use or special operating conditions schedule for harder work.

Fleet vehicles often belong on the second one. Ford's 2020 Super Duty owner's manual, for example, lists these as severe use:

• moderate to heavy loads or towing;
• mountainous or off-road driving;
• extended idling;
• extended hot or cold operation.

The same manual also points to its special operating conditions for dusty conditions such as unpaved roads.

A single "every 8,000 km" rule for the whole fleet is simpler to run, but it can under-service a van that idles all day and over-service a car that only drives the highway (our reading of how the two schedules differ). If you standardize, standardize on the stricter schedule for each vehicle type.

How often should each vehicle be serviced?

By distance, time or engine hours, whichever comes first. Three clocks run on every vehicle, and each one wears different parts:

Engine hours are the easiest clock to overlook. An idling engine adds no distance, but it still runs. Ford's Super Duty manual says, in its scheduled maintenance section: "For every hour that your vehicle idles, it accumulates the equivalent of approximately 25 mi (40 km)." That figure is Ford's, for that truck; other makers may count idle time differently, or not at all. Many newer vehicles also have an oil-life monitor. Ford's "determines when you should change the engine oil based on how you use your vehicle."

Cutting idle time helps here too. See how much idling costs a fleet.

What does the law require, and for which vehicles?

In the US, the Federal Motor Carrier Safety Regulations apply to commercial motor vehicles (CMVs). Under 49 CFR § 390.5, that includes a vehicle used in interstate commerce with a gross vehicle weight rating (GVWR), gross combination weight rating, or actual gross or combination weight of 4,536 kg (10,001 lb) or more, whichever is greater. It also covers some passenger vans by seating capacity, and vehicles carrying placarded hazardous materials.

For those vehicles, 49 CFR Part 396 requires the motor carrier to:

• "systematically inspect, repair, and maintain" every vehicle it controls, with parts and accessories "in safe and proper operating condition at all times" (§ 396.3(a));
• keep records for each vehicle it controls for 30 consecutive days: its identification, "the nature and due date of the various inspection and maintenance operations," and a dated record of inspections, repairs and maintenance (§ 396.3(b)). Records are kept for one year, and for six months after the vehicle leaves the carrier's control;
• inspect each vehicle periodically. A CMV may not be used unless its components have passed an inspection "at least once during the preceding 12 months" (§ 396.17(c));
• act on driver reports of defects before the vehicle is driven again (§ 396.11).

Most cars, compact SUVs and half-ton pickups have a GVWR below 4,536 kg (our general observation; check each vehicle), so on their own these federal rules don't apply to them. Some heavier pickups and vans come close to it or pass it, so check the GVWR on each vehicle's door-jamb label. Because combination weight counts, a pickup towing a trailer can cross the line (our reading of § 390.5). States set their own rules for trips that stay inside the state, and Canadian provinces apply the National Safety Code. Name your jurisdiction and check it; this article isn't legal advice.

Even where the rules don't apply, § 396.3's record list is a good template for any fleet.

A practical schedule for a small light-duty fleet

This is our suggested structure, built from the sources above. The intervals themselves come from each vehicle's schedule.

Tires. Transport Canada's Riding On Air guide says to measure pressure "at least once a month" with the tires cold, meaning parked for at least three hours or driven no more than 2 km. It also says to look for "uneven tread wear, cuts or cracks, bulges" monthly, and to replace tires worn to the tread-wear indicator (1.5 mm, or 2/32 in). Use the pressure on the vehicle's tire label, not the maximum on the sidewall.

Recalls. Transport Canada tells owners to look up recalls by VIN on the manufacturer's website or the national database, and that "you're responsible to stay up to date on recalls." In the US, NHTSA offers a similar free recall search by vehicle or VIN. A monthly check across the fleet takes minutes (our estimate).

Batteries. Varta advises having batteries checked "at least once a year before winter." A fleet has more of them to track; see when to replace fleet batteries.

What records should you keep for each vehicle?

One record per vehicle, covering the four points below. A spreadsheet works for a handful of vehicles. For each one, record:

1. Identity: unit number, make, model, year and VIN.
2. What's due and when: the next service by distance, date and engine hours.
3. History: every inspection, repair and service, dated, with the odometer reading.
4. Open items: driver-reported defects, open recalls and active warning lights, with the date raised and the date fixed.

That list mirrors 49 CFR § 396.3(b). Using it for light-duty vehicles too means that, if a vehicle ever crosses into CMV territory, the paperwork is already right (our suggestion).

Let the vehicles tell you what's coming

Scheduled service catches wear. Faults show up between services:

• Driver reports. Make it easy and routine for drivers to report a warning light, noise or pull; our pre-trip inspection guide covers what to check.
• Diagnostic codes. A pending code can appear before the check engine light does. See pending, stored and permanent codes and what OBD-II data can tell a fleet manager.

Safety. Some faults shouldn't wait for the next service. Take a vehicle out of service and have it inspected if it has a brake warning light, a soft or sinking brake pedal, a fluid leak under the brakes or fuel system, a smell of fuel, a flashing check engine light, or overheating. Read the owner's manual for each warning light's meaning.