Fuel is typically the largest variable cost in a fleet and the one with the most levers. It is also the area where fleets most often assume they are already efficient because nobody has measured the alternative.
Where the money goes
| Factor | Typical influence |
|---|---|
| Distance driven | Direct; reduced by routing and territory design |
| Driving style | Large; acceleration, speed and braking behaviour |
| Idling | Often substantial and almost entirely recoverable |
| Vehicle specification | Engine, aerodynamics, tyres, weight |
| Payload | Heavier vehicles use more; also a routing consideration |
| Tyre pressure | Under-inflation measurably raises consumption |
| Maintenance condition | Filters, injectors, brakes binding |
| Route type | Urban stop-start versus motorway running |
| Fuel purchasing | Price per litre, card discounts, bunkered fuel |
| Losses | Theft, card misuse, unrecorded personal use |
The order matters. Purchasing terms attract most management attention and are usually the smallest lever. Behaviour and idling attract the least and are usually the largest.
Fleet-wide averages hide everything. A vehicle whose consumption has risen 12% against its own six-month baseline has a specific, findable cause — usually tyres, a fault, or a new driver.
Measure consumption honestly
Litres per 100 km or miles per gallon, per vehicle, from telematics fuel data where available, cross-checked against fuel card purchases. The two sources disagree frequently, and reconciling them is itself a control.
Segment by:
- Vehicle class
- Route type — do not compare urban and motorway vehicles
- Season — winter consumption is higher
- Load profile
Then compare each vehicle against its own baseline and against its class peers. Deviation from a vehicle's own history is the strongest signal: it indicates a mechanical problem, a driver change or a route change, and all three are worth investigating.
Fuel card control
Fuel cards are convenient and a persistent source of loss. Controls that work:
- Card assigned to vehicle, not to driver, with the driver identified at the pump by PIN
- Mandatory odometer entry at the pump, validated against telematics
- Purchase limits by volume, frequency and time of day
- Product restrictions — fuel only, no confectionery, no non-vehicle purchases
- Exception reports, reviewed weekly:
| Exception | Indicates |
|---|---|
| Volume exceeds tank capacity | Filling another vehicle or container |
| Vehicle position far from the station at transaction time | Card used without the vehicle |
| Two transactions within a short interval | Multiple fills |
| Consumption deviating sharply from baseline | Theft, fault, or driver change |
| Odometer entry inconsistent with telematics | Falsified entry |
| Purchases outside working hours | Personal use |
Cross-referencing transactions against telematics position is the single most effective control, and it is a straightforward join between two data sets most fleets already hold. Fleets running it for the first time commonly find issues they were not aware of.
Behaviour
The largest recoverable saving in most fleets.
- Idling. Report it weekly per vehicle, normalised per engine hour. Discuss it. Idling frequently falls substantially through visibility alone.
- Speed. Fuel consumption rises steeply above a certain point, particularly for heavy vehicles. Speed limiters and coaching both work.
- Acceleration and braking. Anticipation saves fuel and reduces brake and tyre wear simultaneously.
- Route adherence. Drivers deviating from planned routes add distance; consistent deviation is usually a routing data problem worth investigating.
Link this to your driver behaviour programme rather than running a separate fuel initiative — the same behaviours drive both.
Specification and maintenance
- Aerodynamics on high-mileage vehicles: deflectors, side skirts, well-fitted bodywork
- Low rolling resistance tyres where the duty cycle suits them
- Tyre pressure management, the cheapest single measure available
- Weight reduction — unnecessary equipment and permanent load carried all year
- Maintenance condition — air filters, injectors, binding brakes, wheel alignment
- Right-sizing — a vehicle consistently operating well below capacity is burning fuel to carry itself
Purchasing
Worth attention, though usually smaller than the operational levers:
- Negotiated discounts against a published index rather than pump price
- Preferred site networks with better rates, built into route planning where practical
- Bunkered fuel where volumes justify the storage, with proper controls
- Avoiding motorway and premium-site fuelling through route planning
- Fuel duty recovery where your jurisdiction and operation permit it
Questions readers send us
How much can we realistically save on fuel? Fleets that have never managed idling, behaviour or tyre pressure typically find meaningful savings across those three areas combined. Fleets already managing them will find far less, and should focus on specification and route efficiency instead. Measure your own starting point rather than assuming a percentage.
Is idling really that significant? In fleets that have never measured it, stationary engine time is frequently a substantial share of total engine hours. It burns fuel, adds engine hours that trigger earlier servicing, and produces emissions with no output. It is usually the fastest available saving.
Should we fit speed limiters? Where legally permitted and operationally acceptable, they produce consistent savings and safety benefits. They also attract driver resistance, so explain the reasoning and set the limit thoughtfully — an unnecessarily low limit costs route time and goodwill.
How do we detect fuel theft? Cross-reference card transactions with vehicle position and tank capacity, monitor consumption against each vehicle's own baseline, and require odometer entry validated against telematics. Most detection comes from the combination rather than from any single check.
Do fuel cards from a single supplier save money? Usually on administration and often on price through negotiated discounts, at the cost of network flexibility. Model the trade-off against where your vehicles actually refuel — a discount at sites your routes never pass is worth nothing.
