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Engine Idling and Fuel Consumption

By Verizon Connect Team June 27, 2022

How Much Fuel Does Idling Waste? What Does Engine Idling Mean for Your Fuel Tank

There are some serious implications of engine idling when it comes to fuel efficiency. Excessive motor vehicle idling leads to increased fuel consumption which not only increases wear on engine components and shortens vehicle life, but also negatively impacts the environment. Fortunately, there are ways to reduce unproductive engine idling. In this article we’ll discuss why idling engines can cost you a lot and are bad for the environment, and some potential solutions for fleet managers. 

What is engine idling? 

Idling” refers to running a vehicle’s engine when it’s not moving, such as when you’re at a red light, stuck in traffic or parked at a spot. Idling is a part of driving and is a fairly common occurrence for most drivers. However, idling may not be the best thing for your vehicle, fuel consumption, or the environment. 

Reducing the amount of time vehicles are idling is a simple way to maintain and even increase fuel economy among fleet vehicles, especially as fuel prices continue to rise. 

Is idling bad for your engine? 

Letting a vehicle idle does more damage to the engine than starting and stopping. In fact, running an engine at low speed (idling) causes twice the wear on internal parts compared to driving at regular speeds. 

“Excessive idling has a negative effect on the engine and exhaust system and increases maintenance costs.” “For instance, extended idle operation may lead to reduced efficiency of engine lubricants (increase in frequency of oil change), engine or spark plug wear/fouling and accumulation of fuel residue in the exhaust system”.

Excessive idling can also cause a build-up of carbon residue in a truck’s engine. Because the engine is not operating at its optimal temperature when idling, fuel is only partially combusted, leading to fuel residue build-up on the cylinder walls. This can further damage engine components, including spark plugs and exhaust systems, increasing maintenance costs and shortening the life of the engine.

Idling and fuel consumption 

Does idling waste fuel? Yes, it does. Idling vehicles can use more fuel than you might realise. This directly affects how much you spend on gas and how often you need to refuel. How much fuel a vehicle consumes while idling depends on factors such as its, weight, engine size, and the type of fuel it uses. “Idling can use up to 2 litres of fuel per hour, emitting over 5.26kg of CO2”.

Some countries even have anti-idling laws that restrict engine idling and impose fines on drivers who violate them like the UK, France and Germany. 

Download this free guide to find out effective ways to bring down fuel costs. 

Engine idling and the environment in New Zealand

Idling and wasting fuel have a serious impact on the environment. The World Health Organization estimates that air pollution is responsible for 4.2 million deaths each year. Particulate matter (PM) is made up of solid and liquid particles in the air, both from natural and man-made sources. When PM is inhaled, it can cause health problems. In New Zealand, these health problems associated with PM range from respiratory irritation, heart problems, lung cancer, and even premature death. 

In Australia, a report on Transport Energy/Emission Research recently found that “passenger vehicles are likely idle more than 20 percent of their drive time. The report found that engine idling contributes up to 8 per cent of total carbon dioxide emissions over the journey, depending on the vehicle type. To put that into perspective, removing idling from the journey would be like removing up to 320,000 cars from New Zealand roads”.

Potential solutions for engine idle reduction 

For many people, reducing excessive idling is a priority, if not a necessity. For instance, though everyone can benefit from fewer idling vehicles on the road, business owners who have to manage their fleet of vehicles stand to save money by reducing idling time.

  1. For drivers of small vehicles, it is recommended to turn off your engine if you plan to idle for longer than 10 seconds. It is a common myth that restarting your engine uses more gas and causes engine wear

  2. Don’t spend time idling to warm up your engine - just start driving. Engines warm more quickly when they are being driven than when idling.  In cold weather you may deem it necessary to idle before you start your journey, but this just wastes fuel. The best advice is to start slowly and go easy on the accelerator for about 5-15 minutes when driving in cold weather. Failing to do this could stress out the engine before it’s had the chance to reach its normal performance levels

  3. GPS fleet tracking software is one of the feasible ways to reduce idling in fleets. This software can be used as an idle time tracking software and gathers data about what vehicles and drivers are actually doing, so fleet managers can see if there are any ways to improve performance and decrease time spent idling
  4. Continually train and coach drivers to reduce excessive idling. Coaching should be ongoing, but teaching drivers to avoid idling from when they’re first hired can help establish best practices early on. Guidelines for engine idling should be part of your training program and safety culture

  5. Fleet managers and individual operators should consider purchasing auxiliary power units (APUs) to reduce engine idle time. APUs can power trucks during rest periods without using fuel so that drivers can enjoy the comforts of their cabins, such as AC and lights, without burning fuel

Engine idling may seem harmless, but it actually has tremendous impacts that can negatively affect everyone. It wastes a significant amount of money on fuel and puts harmful toxins into the environment. Keep engine idling at the forefront of your mind when driving so that you can do your part to reduce it. 

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Verizon Connect Team

The telematics industry is moving at a fast pace. With new developments, use cases and feature sets emerging every day, it can be challenging to make the right decision for your fleet business. Verizon Connect Staff is conceptualized to be a partner for your business and help you make smart choices based on useful content.


Tags: Cost Control, Field Management, Inspections, Performance & Coaching, Revenue & ROI, Vehicle Maintenance