1. Home
  2. /
  3. Fleet management
  4. /
  5. How Much Fuel is...

How Much Fuel is Wasted By Idling in Cars, Vans and HGVs?

Aug 22, 2023

In this post, we’ll explain just how much fuel might be wasted by idling and discuss the issues this might cause – whether you’re a private driver or a fleet manager.

For more information on how we can help you and your fleet, get in touch with us on 020 8290 9099 or email us at commercial.motor@anthonyjones.com.

What is Engine Idling?

Engine idling means letting an engine’s vehicle run while it’s stationary. Most drivers idle when sat in traffic, while waiting for lights to change, or when dropping off or picking up passengers or deliveries.

Idling greatly increases both fuel consumption and air pollution. So if you’re a fleet manager, idling might be costing you more than you think.

The Effects of Idling

Idling increases the levels of exhaust emissions a vehicle makes over the course of a journey. As exhaust emissions contain numerous harmful gasses, idling contributes to the 40,000 annual UK deaths that are linked to air pollution.

But idling also wastes fuel. One study found that cars may use up to an extra gallon of fuel for every hour the engine’s left idling.

How Much Fuel is Wasted By Idling in HGVs and LGVs?

The Transport Research Laboratory (TRL) studied how idling effects the fuel consumption in HGVs and LGVs. They found that just one minute of idling can cause an HGV to consume up to 21.7g of fuel and emit 68.64g of CO2. This amounts to a cost of about 3p per minute in fuel.

A study in the US by the National Renewable Energy Laboratory found that commercial vehicles are idling for 1 to 4 hours a day, on average.

So if a HGV were to idle for the lower average of 1 hour a day over the course of six months, it would amount to over £348 of fuel wasted. And since fuel prices have risen significantly since TRL conducted this study, the costs today would be much higher.

The bigger your fleet, the bigger your costs. Multiply the amount of fuel wasted by the number of vehicles in your fleet, and idling could be costing you thousands of pounds a year.

On top of this, idling also contributes to premature engine wear and tear. So all of that thoughtless idling could also be impacting your maintenance and repair costs.

Are There Any Laws Against Idling?

Rule 123 of The Highway Code states that you must not leave a parked vehicle unattended with the engine running. Nor may you “leave a vehicle engine running unnecessarily while that vehicle is stationary on a public road”.  You can get a fine between £20 and £80 if you’re caught doing so.

The Code advises that if your vehicle’s stationary and is likely to be for more than a couple of minutes, you should “apply the parking brake and switch off the engine.” However, you’re allowed to leave the engine running if you’re stuck in traffic or diagnosing faults.

So there are no real laws against most kinds of idling. If you’re stuck in traffic, it’s up to you to switch your engine off to reduce your fuel consumption and emissions. And if you’re a fleet manager, there are ways you might encourage your drivers to reduce their idling.

How To Reduce Idling in Your Fleet

For HGVs and LGVs, some idling is unavoidable, or even necessary. For example, drivers may need to keep the engine running to maintain an adequate temperature in the cab to meet their hours-of-service requirements. Also, keeping the engine running is sometimes necessary to keep cargo at the required temperature for transport, or to build up adequate air pressure for the brakes.

But if you take to monitoring your drivers’ behaviour, you might identify some periods where your drivers are idling unnecessarily. With good telematics software, for example, you can get a picture of any driver’s idle minutes per stop, as well as their total idle minutes per day. If any of your drivers are idling more than others, you can take further action – such as arranging some additional training.

Some tracking software also allow you to send automatic alerts to drivers after a set period of idling. For example, you could notify your drivers should they let their engine idle for, say, more than 20 minutes, while setting specific parameters for certain drivers and vehicles in your fleet.

Read our full guide to managing driver behaviour in your fleet.

For more information on how we can help you and your fleet, get in touch with us on 020 8290 9099 or email us at commercial.motor@anthonyjones.com.


Get a Quote

You can call us during normal office hours, Monday to Friday, 9am to 5pm. Outside of office hours you can either email us or leave an answerphone message and we promise to get back to you the next working day.

General enquiries:
020 8290 4560

Sign up for news

* indicates required