Here’s a sobering fact: a new work truck might deliver, say, a 5% bump in fuel economy on paper, but the person behind the wheel can swing that number by 30% in either direction. With fuel prices squeezing operating budgets, that gap represents a significant cost-reduction opportunity.

Working with our clients on telematics rollouts and fuel programs, I frequently hear some version of the same question: Why are some of our trucks burning so much more fuel than others when they’re running comparable routes and logging comparable mileage?  In virtually all cases, my answer is: your drivers.

Driver Behavior Has the Biggest Impact on Fuel Economy

With fuel prices shaped by supply, demand, and geopolitics, the person behind the wheel is the single largest controllable factor in your fuel spend and, therefore, the key to fuel efficiency. To convert drivers from fuel wasters into fuel savers, fleet managers should first examine the four habits most responsible for fuel waste, with the help of telematics and route data:

1. Speeding

The U.S. Department of Energy (DOE) estimates that every 5 mph driven over 50 mph is roughly equivalent to paying an extra $0.18 per gallon at the pump. A truck cruising at 65 instead of 75 will post a noticeable improvement in fuel consumption, and on a vehicle covering 100,000 miles a year, those savings add up quickly. In the fleet data we review with clients, a small group of “lead feet” tends to account for a disproportionate share of speeding incidents, making targeted coaching especially manageable and effective.

2. Hard Acceleration and Braking

An MIT analysis cited by the DOE shows that aggressive driving can lower fuel economy by 15% to 30% at highway speeds and 10% to 40% in stop-and-go conditions. Every time a driver punches the throttle, the engine's fuel consumption spikes. And when drivers brake hard, fuel is converted to heat and brake wear rather than forward motion.

The fix? In a word, it’s: anticipation. Drivers who think one or two cars ahead, coast toward red lights, and ease into acceleration burn measurably less fuel.

3. Excessive Idling

This is where the data can become genuinely surprising. Argonne National Laboratory estimates that idling vehicles waste roughly 6 billion gallons of fuel a year in the U.S. To put that in perspective, that’s enough fuel for a 20-mpg pickup truck to travel the distance equivalent to more than 400 round-trip trips to Mars. So, clearly, idle time is not a rounding error.

The DOE notes that a heavy-duty truck can burn up to 0.8 gallons of fuel per hour while idling, and that idling for more than about 10 seconds uses more fuel than shutting down and restarting the engine. Some fleets run power take-off (PTO) equipment, and significant idle time is unavoidable. However, for a driver lingering at a customer site or running a non-work-related errand, the cost is pure waste. For heavier vehicles, this can add up to hundreds, even thousands, of dollars per truck per year.

4. Route choice and distractions

Two trucks dispatched to the same job site will often take different paths and therefore arrive with different fuel burn rates. Some of that variance is unavoidable. But when drivers default to familiar routes over efficient ones or backtrack because of a missed stop, the cost shows up in your monthly fuel reporting. Distraction also plays a role. A driver glancing at a phone is more likely to brake hard, miss a turn, and accelerate hard to make up time. Each of those events carries a fuel penalty.

A clearer picture emerges when you layer route data onto behavior data. A driver working a tight urban route with constant traffic and short turn windows is not, of course, in the same situation as one running open-highway miles, even when their raw mpg numbers look similar.

Pairing GPS history with telematics behavior scores helps fleet managers distinguish drivers who genuinely need coaching from those simply operating under tougher conditions. It also identifies where smarter dispatch and routing decisions can reduce fuel consumption.

In addition to tracking and managing these four key driver behaviors, here are some other fuel-savings considerations:

Using Telematics and Fuel Data to Identify Fuel Waste

A fuel card program offers valuable additional insight. For example, Wex’s reporting and analytics tools allow fleet managers to spot anomalies at the pump, including out-of-network purchases, off-hours fills, and consumption that exceeds the vehicle profile’s predictions.

When you cross-reference fuel card data with telematics activity, patterns surface quickly. A driver whose mpg is well below average and whose harsh-event count is well above it is a coaching opportunity hiding in plain sight.

Driver Coaching and Incentives Improve Fuel Efficiency

Data alone does not change behavior; it must be paired with feedback that drivers can use. Real-time alerts in the cab help drivers self-correct in the moment, which research consistently shows is more effective than a performance review weeks later. Eco-driving training, when reinforced over time, can produce fuel savings of as much as 5% to 30%. The DOE’s Alternative Fuels Data Center recommends pairing drivers with coaches who can identify specific opportunities, like coasting before a red light or limiting idle time to 30 seconds or less.

Incentive programs make driver data feel less like surveillance and more like a scoreboard. So, consider monthly recognition for the most improved driver, a gift card for the safest scorecard, or even a friendly leaderboard at a terminal. These small and relatively easy-to-execute gestures can lead to the real prize: a lasting cultural shift. Once drivers see that your fleet is paying attention to fuel usage and rewarding progress, the cost-reduction habits tend to stick.

How to Reduce Fleet Fuel Costs Through Driver Behavior

If you want a place to begin, pick one metric and one quarter. Idling is often the easiest target. Pull a baseline from your telematics data, communicate a clear goal to your drivers, and report on progress weekly. Most fleets we work with see meaningful movement within 30 days, and the financial case is straightforward enough to justify a deeper investment in driver coaching, training, and reporting.

Fuel will keep doing what fuel does: rise, fall, and then rise again. There’s no controlling that. What you can control is what your drivers do between fill-ups. If you get that piece right, you’re sure to reduce your fuel costs and, in so doing, improve your fleet’s safety record and cut down on air pollution. What’s not to like about all of that?

About the Author: Sarah Richey is Manager of Products and Implementation at Mike Albert Fleet Solutions, where she helps fleet clients translate technology investments into measurable results. Under her leadership, organizations across a range of industries have adopted solutions such as telematics to improve safety and efficiency while controlling costs. This article was authored and edited following Work Truck editorial standards and style. Opinions expressed may not reflect those of WT.