Car sharing & eco-driving tips

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Anti-Idling for Cleaner Air

Idling your vehicle—running your engine when you’re not driving it - truly gets you nowhere! It reduces your vehicle’s fuel economy, costs you money and creates pollution.

The problem is that stationary cars release up to twice as many exhaust emissions as when the car is moving. These pollutants have detrimental effects on human health and affect everyone living in urban areas. These pollutants are especially bad for people with asthma, heart and respiratory conditions, children and the elderly.

It has even been shown that poor air quality leads to 40,000 premature deaths each year in the UK. Compare this to the 1,713 deaths from road traffic accidents and we see that 

this is a significant problem. People can be affected by poor air quality even if they never experience any noticeable pollution related-health effects such as breathing problems. Air pollution can cause short term (nearly immediate) symptoms and long term (chronic disease) effects.


St Albans City and District Council are committed to reducing uneccessary engine idling as a means to improving local air quality, preventing health impacts and reducing greenhouse gas emissions. As part of the Switch Off For Cleaner Air campaign we are asking drivers to switch off their engines if they are to be stationary for longer than a minute.

Some interesting facts

MYTH...It is better to idle the vehicle as turning the engine off and on wears it out.

TRUTH...No. Ignitions in modern cars have eliminated this problem. Idling dirties your engine with incomplete combustion increasing wear and tear. Excessive idling lets water condense in the vehicle’s exhaust system, which can lead to corrosion. It also causes spark plugs to become dirtier more quickly. This can cause an increase in fuel consumption by 4-5%.

MYTH...When it’s cold I need to keep my vehicle and passengers warm or warm up my engine.
TRUTH...It can take up to an hour for an engine to cool down. Turning off your engine, but keeping the ignition on and the fan blowing, will provide warm air for some time.

MYTH...Catalytic converters need to be hot to work properly.
TUTH...Yes, but an idling engine does not keep a catalytic converter warm. They retain their heat for about 25 minutes after an engine is switched off.

MYTH...Starting an engine causes more pollution than idling.
TRUTH...No. Turning off an engine and restarting it after a minute or longer causes less pollution than keeping the engine idling and uses less fuel.

MYTH...It doesnt make any difference if I run my engine a few minutes longer.
TRUTH...If all drivers in central London switched off their engines, rather than idling unnecessarily, for 1 minute each day this could reduce PM10 (particulate matter) emissions by at least 286g per day (at least 90kg per year).

Greener Driving Tips

By driving smarter, you could save £300-£350 each year. Eco-driving is about driving in a style that reduces fuel consumption, noise and greenhouse gas emissions. 
  • Reduce load and drag: remove any excess weight or any attachment which causes drag so that your car doesn't need to work harder to accelerate. 
  • Plan ahead: plan unfamiliar journeys and check the traffic in advance to avoid wasting fuel getting lost or stuck in traffic. 
  • Combine short trips: cold starts use more fuel so try to combine errands into one journey.
  • Switch off when idling: idling wastes fuel so it is better to switch the engine off if you are likely to be stationary for more than a minute or two. Modern cars use virtually no extra fuel when they are re-started without pressing the accelerator so you won’t waste lots of fuel turning the car back on.
  • Drive smoothly: anticipate the road ahead to avoid unnecessary braking and acceleration. Decelerate early when slowing down.
  • Keep moving: try and keep the car moving rather stopping and starting, by anticipating the road ahead of you. Don’t roll out of gear though as you won’t have full control of your vehicle. 
  • Shift to a higher gear early: change up a gear at around 2000 and 2500 rpm. This makes such a difference to fuel economy that all cars in the future are likely to be fitted with an indicator light which will show the most efficient gear change points.
  • Air-con: air-conditioning uses more fuel at low speeds, but at higher speeds the effects are less noticeable. Try and keep the air conditioning for high speed driving. Aim to run it at least once a week throughout the year to maintain the system in good condition. 
  • Electricals: electricals in your car increase fuel consumption so turn off your heated rear windscreen, demister blowers and headlights, when you don't need them.
  • Slow down: the faster you drive the more fuel you consume. For instance, driving at 85 mph uses 25% more fuel than at 70 mph. 
  • Consider alternatives: if you only need to travel a few miles, consider walking or cycling.
  • Servicing: Get your car serviced regularly to maintain engine efficiency
  • Maintenance: make sure you use the right specification of engine oil for your car and check your tyre pressure regularly. Under-inflated tyres create more resistance and so use more fuel.

Car sharing

Car Share

By sharing a vehicle with others who are making the same journey, you can benefit from the convenience of a car whilst alleviating some of the associated problems such as congestion and pollution. 

There are many websites available such as Herts Liftshare and Bla Bla Car which can help you link up with other local people who are willing to car share. Just think, your next drive to work might be in a BMW!

Buying a new car

If you're thinking of replacing your car then now is the time to do a bit of research to see what vehicles are available which suit your needs but also save you money in the longer term. The Department for Transport provides online tools for determining the fuel consumption, emissions performance and tax banding of a wide range of vehicle makes and models to help you decide. 

With the infrastructure for electric vehicles growing, it's also a great time to be thinking about purchasing an electric car.

Date of last review: 29 November 2016