How much diesel does a truck use per mile?

As you’d expect, the average fuel consumption for a truck will depend on its size and payload.  

We break down the average consumption of diesel by truck type below, assuming the trucks are traveling on motorways. If you’re interested in diesel consumption per mile, you’re likely interested in finding ways to save on your fleet’s fuel costs. We’ll therefore also cover factors that impact your fuel consumption, with some expert insights on saving fuel.  

Need a quick way to figure out your diesel costs? Scroll down to the free fuel consumption calculator in the section titled “How to calculate diesel consumption for trucks.”  

Average diesel consumption per mile for different types of trucks

As noted in the FAQs on our truck fuel efficiency page, a truck’s average fuel efficiency is 30 to 40 litres of diesel for every 62 miles/100km driven. By our estimates, larger trucks with a payload of around 23.5 tonnes consume as much as 38 litres per 62 miles on average. A small truck with a payload of around 16 tonnes uses roughly 25 litres of diesel per 62 miles.   

Light commercial vehicles weigh under 3 tonnes, so they of course consume less fuel than larger and heavier transport trucks. . Ecostars Europe calculates that a light commercial vehicle consumes about 9 litres of fuel for every 62 miles it travels. That’s approximately a third of what a heavy goods vehicle (HGV) consumes for the same distance. 

It’s worth noting that from 2035 on, all new trucks under 26 tonnes that are sold in the UK must be zero emission. By 2040, new trucks weighing more than 26 tonnes must be zero emission. Heavy goods vehicles (HGVs) are harder to electrify than vans and cars. That probably explains why the UK government is investing in testing projects for zero-emission trucks. In the meantime, transport fleets need to be able to operate as efficiently and sustainably as they can on diesel. 

Factors that impact diesel consumption in trucks 

The four factors with the biggest impact on a truck’s fuel efficiency per mile are: 

1. Speed and gear changes 

Like any other vehicle, a truck that’s travelling at a constant speed will consume notably less fuel than a truck that frequently changes speed and shifts gears. Traffic jams and road construction will lead to higher fuel consumption, since your truck driver must alternate between accelerating, shifting gears and braking. 

2. Hills and corners 

To climb hills, a truck needs more engine speed than it does on a relatively flat road. More engine speed of course necessitates more power—hence stepping on the accelerator and consuming more fuel. A heavily loaded truck needs to slow down quite a bit to navigate corners safely. Regaining speed requires fuel-guzzling acceleration. At times, a truck may even be climbing a hill and rounding a corner, which will of course lead to higher diesel consumption per mile. 

3. Vehicle and load weight  
The heavier a vehicle is, the more fuel it will consume. According to Smith Bros., research shows that a 10% increase in gross vehicle weight can result in a 5% increase in fuel consumption. So, the fuel costs for transporting heavier loads can be substantially higher than lighter runs.  

4. Aerodynamics 

Unlike passenger cars, HGVs can often lack the aerodynamic features that reduce drag. But in 2022, the Department for Transport introduced legislation to allow the use of aerodynamic features on heavy goods vehicles. The UK government cites a study from 2013 showing that aerodynamic improvements to HGVs could lead to savings of 7% to 15% in fuel.

How to calculate diesel consumption for trucks  

Looking for the simplest way to calculate your diesel consumption per mile? Try our simple fuel consumption calculator below. All you need to do is plug in a few details: expected mileage, your truck’s average fuel efficiency in miles per gallon and the fuel cost. 

In case you’re curious about the methodology our fuel consumption calculator uses, we’ll give you the mathematical formula for it right now:  

Expected mileage ÷ Average miles per gallon x 4.54609 x Fuel price per litre = Fuel cost 

In the UK, we measure fuel efficiency in average miles per gallon but pay for fuel by the litre. It’s therefore necessary to do a miles-per-litre conversion, which is where the gallon x 4.54609 part of the formula comes in (an Imperial gallon is 4.54609). 

This formula, along with our fuel consumption calculator, works for any type of vehicle and any standard fuel type. Which means that if you operate a mixed fleet, you can easily calculate the fuel consumption for all your vehicles, be they trucks, cars or vans. Try it right now:

How to reduce a truck’s diesel consumption  

Getting the most out of your fuel spend is essential to your bottom line. Fuel efficiency is also key to your fleet’s ability to reduce its carbon emissions. Here’s a high-level overview of effective ways to reduce the diesel consumption of your trucks. 

• Adopt fuel-efficient driving: Driving behaviours like speeding, idling and harsh braking or acceleration contribute to higher fuel consumption. Adopting fuel-efficient practices like traveling at lower speeds and using cruise control can reduce fuel consumption by as much as 15%. (Consider that just one minute of idling can burn nearly 22g of fuel and produce about 69g of CO₂ emissions.) 
  

• Provide eco-driving training: According to Fleet Europe, training your drivers in eco-driving can net you an average 6% in long-term savings on fuel. That’s a significant reduction on your fuel spend, not to mention on your CO₂ output. 
  

• Optimise your routes: Want to get more jobs done while also saving fuel? With route optimisation, you use real-time data and professional navigation to efficiently plan and map out your deliveries. 
   

• Schedule in maintenance: Keeping your vehicles in good working order goes a long way when it comes to saving fuel and improving mileage. Schedule in regular maintenance to ensure your vehicle tyres and engines perform at the highest level. 

Fuel management is a big topic for any fleet. If you’d like to explore more fuel-saving strategies and practices, visit our fuel management page. 

How to save up to 15% on your diesel consumption

 As mentioned above, adopting fuel-efficient driving across your fleet can save you up to 15% on your fuel spend. So how do you go about it? 

The challenge lies more in monitoring a fuel-efficient driving policy than it is in implementing one. That’s because you need a reliable way to assess progress towards any fuel-saving goal. You want to be able to track your fuel use over time, drawing historical and real-time insights about your fleet’s diesel consumption. 

A telematics solution like Webfleet provides you with historical and real-time data on your fleet’s fuel consumption. You can evaluate and compare historical fuel consumption and CO₂ emissions with the corresponding dashboards and reports. And with professional Driver Terminals, you can keep your drivers on the safest, most fuel-efficient routes. Check out our page on truck fuel efficiency to explore how you can achieve your fuel-saving goals. 

Wondering what fleets like yours achieve with a telematics solution? Hear what Webfleet customer W.S. Dennison says: “Not only have we benefited from a 15% reduction in fuel costs and CO₂ emissions; we are making incredible savings on vehicle maintenance.”  

If you’re ready to save fuel with a telematics solution, book a free consultation with one of our experts. We’ll show you how to cut your fuel costs—and we’ll show you how to reduce your carbon emissions, meet all your compliance obligations and run a more sustainable fleet. 

This is a new version of a highly popular post that was first published in February 2020. It has been updated with the latest research and features far more comprehensive insights.