Fuel is not the largest cost item for a trucking company; driving personnel rank higher. It is, however, the most volatile cost item. For a diesel-powered articulated truck, fuel accounts for about one-fifth of the cost of goods sold (source: CNR, 2026). And that one-fifth fluctuates without warning: between February and April 2026, the commercial diesel price index for heavy-duty trucks rose by 42.7%, with an impact of nearly 9% on production costs.
Faced with this rise in fuel prices, two operators do not absorb the shock in the same way. The one who knows the actual fuel consumption of each truck adjusts quickly. The one who operates blindly suffers. The difference comes down to one word: visibility.
Telematics provides this visibility. It refers to the suite of onboard tools that collect and transmit vehicle data in real time: fuel consumption, speed, engine RPM, braking, and distance traveled. No technical jargon is needed to understand the concept. You measure what’s happening on the road, so you can take action based on that information.
This article explains where differences in fuel consumption between vehicles come from, what data telematics provides, and how operators use it to reduce their fleet’s fuel consumption.
Two identical trucks, on the same route, can show fuel consumption differences of several liters per 100 kilometers. Whether it’s a rig or a tractor-trailer, the average fuel consumption of a diesel-powered heavy-duty truck is around 33 liters per 100 kilometers. But this average masks significant variations. Four factors account for most of these differences.
This is the number one factor. A harsh driving style, characterized by sudden acceleration and late braking, increases fuel consumption by 20 to 40 percent compared to a smooth driving style. Conversely, fuel-efficient driving relies on anticipation: lifting off the accelerator early, maintaining a constant speed, and shifting up quickly to avoid over-revving. The same vehicle, with the same load, consumes less fuel when the driver anticipates conditions.
A heavy-duty truck engine idling consumes between 2 and 4 liters per hour without moving a single meter. Multiply that by the time spent waiting at loading docks, at traffic lights, and during breaks across an entire fleet, and the cost adds up significantly. Time spent idling is one of the easiest sources of waste to identify and correct.
A detour, a repeated trip through a dense urban area, a route poorly timed with traffic conditions: every unnecessary kilometer costs diesel. Over the course of a route, the accumulation of small route deviations adds up to very real liters of fuel.
The weight carried directly affects fuel consumption. A fully loaded vehicle consumes more fuel than an empty one. The issue isn’t about transporting less, but about transporting more efficiently: avoiding empty returns, consolidating deliveries, and adjusting the load to the specific job. Here again, making these decisions requires knowing exactly how much fuel each run actually consumes.
As long as these factors remain hidden, nothing can be done about them. Telematics makes them measurable. Onboard units, combined with GPS tracking of trucks, continuously transmit a set of metrics directly linked to fuel consumption:
This data is meaningless on its own. Its value lies in putting it into context: comparing one vehicle to another, one driver to the team average, or one week to the previous one. Fuel consumption tracking transforms a hunch (“that truck uses too much fuel”) into a quantifiable fact on which to base decisions.
Having the data is one thing. Taking action based on it is another. Here’s how an operations manager uses it in practice.
The primary use is diagnosis. By tracking fuel consumption vehicle by vehicle, the operator can immediately see when a truck deviates from its average. A sudden spike may indicate a decline in driving style, an emerging mechanical issue, or underinflated tires. Identifying deviations early prevents them from becoming entrenched over weeks.
The data allows each driver to be compared to their colleagues based on objective criteria: sudden braking, idling time, and engine RPM. The goal is not to punish, but to identify areas for improvement. We can identify which drivers would benefit from refresher training and which specific driving habits need improvement. In fact, simply knowing that fuel consumption is being monitored is often enough to reduce it.
By cross-referencing fuel consumption with routes, the operator identifies the trips that use the most diesel. Some are due to terrain or traffic. Others reveal a route that could be improved. This analysis lays the groundwork for the optimization process, discussed below.
The analysis is only valuable if it leads to action. There are four key areas for optimizing fuel consumption.
Eco-driving remains the measure with the best effort-to-result ratio. According to ADEME and training organizations, efficient driving can reduce fuel consumption by approximately 10 to 15 percent, while limiting greenhouse gas emissions—without requiring expensive equipment or increasing travel times. Telematics makes training much more effective: we measure driving habits beforehand, provide training, and measure them again afterward. Progress becomes visible—and therefore sustainable.
Where the analysis identifies fuel-inefficient routes, optimization takes effect. Consolidating deliveries, minimizing empty returns, and scheduling departures outside peak traffic hours are all ways to save fuel by reducing unnecessary mileage. Across a fleet, these planning adjustments add up.
Data on engine speed and idle time aren’t just for driving. They also help track wear and tear. Regular maintenance, properly inflated tires, and appropriate upkeep help minimize fuel consumption. Telematics, by flagging deviations early, supports preventive maintenance rather than reactive repairs.
Fuel efficiency gains can be achieved but are lost if not monitored. Good habits can erode over time. Tracking fuel consumption over time helps maintain results: it shows whether efforts are sustaining, whether a team is slacking off, or whether a new vehicle is aligning with the average. Fuel consumption reduction becomes a standard operating practice, not a one-time effort.
Reducing a truck’s fuel consumption isn’t a one-size-fits-all solution. It’s the sum of various actions: smooth driving, carefully optimized routes, consistent maintenance, and metrics monitored over time. The common thread among these levers is data. Without visibility into actual fuel consumption, every decision is based on intuition. With telematics, decisions are based on facts.
For an operations manager, the challenge isn’t the technology itself. It’s about transforming a fixed expense into a controllable cost. Sinari’s fleet management and in-vehicle computing solutions are designed with this in mind: to give operators a clear picture of their fuel consumption, without unnecessary complexity.