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Avoid Unnecessary Idling

How you drive directly affects the amount of emissions produced by your vehicle. One way to reduce fuel wastage is to avoid unnecessary idling.

Whenever the engine is running and the vehicle isn’t moving, you are consuming fuel, and money, while producing emissions – all without getting anywhere.

Why Avoid Idling?

  • A typical light vehicle burns around 50¢ worth of fuel and emits about 1 kgCO2e of greenhouse gases for every ten minutes of idling – these figures could be double for heavy vehicles;
  • Unnecessary idling in enclosed or poorly ventilated spaces, such as warehouses and depots, exposes staff to increased levels of air toxic emissions; and
  • Avoiding unnecessary idling is one of the easiest ecodriving habits to develop.

Of course, sometimes engines must keep running to drive loads such as refrigeration units or the like.

Modern vehicles do not need to be warmed up before driving. The best way to warm up a vehicle is by driving it. Warming up a vehicle is more than warming its engine – the tyres, transmission, wheel bearings and other moving parts also need to be warmed up for the vehicle to perform well.

Excessive idling can wear or damage engine components such as cylinders, spark plugs and exhaust systems. An idling engine is not operating at its peak efficiency, potentially resulting in incomplete fuel combustion. Fuel residue may condense on cylinder walls, cause glazed pistons, contaminate oil or the like.

Idling can also cause spark plugs to cool, which allows them to get dirtier than if they are operating at peak efficiency. This could lead to misfires or incomplete combustion, wasting fuel.

Many vehicles depend on technology such as catalytic converters to reduce air toxic emissions. If these are not fully warmed up, as is the case with a cold-start idle, the air toxic emissions are considerably higher, and being emitted at your home, depot or wherever your journey begins. Excessive idling may also lead to water condensation in the exhaust system, possibly speeding up corrosion.

Restarting the engine has little impact on the key components such as the battery and starter motor. Component wear from engine restart is typically offset many times over by the fuel savings made by avoiding idling. Idling for more than about ten seconds uses more fuel and produces more emissions than restarting your engine.

If you plan to stop for more than a few seconds – except in traffic – turn off the engine.

Potential Idling Reduction Strategies

  • Designate enclosed areas and areas with poor ventilation as idle-free zones. Support this policy with signage and work instructions;
  • Provide reminders for drivers in the vehicle cabin and staff rooms; and
  • Consider vehicles with built-in anti-idle technology, if applicable.