Monitor vehicle idling

For cost-conscious and environmentally-focused fleet decision-makers and company car and van drivers, the message is clear : don’t be idle !

Emissions whilst idling are harmful to health from the pollution caused, fuel is wasted and  engines can be damaged. Therefore, turning the engine off and restarting it should be adopted as best practice by all drivers.

Myth or fact?

  • Myth 1: The engine should be warmed up before driving.

Reality: Idling is not an effective way to warm up the vehicle, even in cold weather. The best way to do this is to drive the vehicle. With today’s modern engines, no more than 30 seconds of idling is required on winter days before driving away.

  • Myth 2: idling is good for your engine.

Reality: Excessive idling can actually damage engine components, including cylinders, spark plugs, and exhaust systems. Fuel is only partially combusted when idling because an engine does not operate at its peak temperature. This leads to the build up of fuel residues on cylinder walls that can damage engine components and increase fuel consumption.

  • Myth 3: Shutting off and restarting the vehicle is hard on the engine and uses more fuel than if left running.

Reality: Frequent restarting has little impact on engine components like the battery and the starter motor. Component wear caused by restarting the engine is estimated to add almost £10 per year to the cost of driving, money that will likely be recovered several times over in fuel savings from reduced idling.

 (Source : California Energy Commission)


  • Drivers caught in a queue should avoid wasting fuel by turning the engine off if they could be waiting for more than three minutes (1)
  • 10 seconds of engine idling uses more fuel than restarting (2)
  • Each litre of fuel generates 2.4kg of greenhouse gas CO2 (2)
  • Exhaust emissions contain a range of toxic substances such as carbon monoxide, nitrogen dioxide, hydrocarbons and particulates (2)
  • For every two minutes a car is idling, it uses about the same amount of fuel it takes to go about one mile (3)
  • Research indicates that the average person idles their car five to 10 minutes a day (3)
  • The best way to warm the engine and all other components is to drive a vehicle (4)

The issue

Air pollution is estimated to reduce the life expectancy of everyone in the UK by an average of 7 to 8 months, according to the Government’s The Air Quality Strategy for England, Scotland, Wales and Northern Ireland report published in July 2007.

It is for that reason that a number of local authorities, such as West Lothian Council in Scotland, have launched campaigns designed to stop drivers from leaving their engines running when parked or in traffic queues.

The strategy suggests that by taking a series of measures to reduce air pollution, including reductions in engine idling, it could help to reduce the impact on average life expectancy to 5 months by 2020, and provide a significant step forward in protecting the environment.

In addition, putting an end to engine idling will reduce fuel use. If each one of the estimated 80,000 cars on the road in West Lothian idled for just 10 minutes each week, conservative estimates suggest a staggering 416,000 litres of petrol would be wasted each year. That, says the council, would also result in almost 1m kg  of CO2 being pumped into the atmosphere unnecessarily.

Meanwhile, many experts refute claims that keeping an engine warm by idling is beneficial for a vehicle, as fuel combustion is incomplete when the engine is not working at its peak operating temperature, leaving residues that contaminate engine oil and foul spark plugs.

For vehicles with diesel engines, with coolants, switching the engine off will actually keep the engine warmer for longer.

Additionally, frequent stops and starts don’t produce the large amount of harmful emissions seen with cold starts as catalytic converters stay warm for up to 25 minutes after the engine is turned off.

There’s no question about it - idling gets you nowhere. Instead, it wastes fuel and money and damages the environment.

How ProFleet2 can help

ProFleet2 driver profiling identifies how long a vehicle engine is left idling and  armed with such information, fleet decision-makers can start encouraging employees not to leave their engine idle and instead turn it off, with the net result that financial savings and environmental benefits will accrue.Additionally, the possibility of causing damage to engines, which is expensive to repair, when vehicles are stationary but with their engine running will be significantly lessened.

Therefore, ProFleet2 is the solution to putting an end to vehicle idling by delivering enhanced fleet management solutions.

Information sources

  1. AA,
  2. West Lothian Council,
  3. California Energy Commission,
  4. Hamilton County Environmental Services,