
Fuel savings and emission
For Large SUVs (CRV, Terracan etc): Min. 22 Liters saved per car/year and 60 KG lesser CO2 per year.
Regular Cars (Esteem, Logan etc): Min 15 Liters saved per car/year and 50-60 KG lesser CO2 per year.
2 Wheelers and Rickshaws: Min 5 Liters saved per bike/year and 10 KG lesser CO2 per year in our already molested atmosphere!!!!
Now branded petrols in India like Speed, Xtra Premium cost Rs. 58-59. For a large SUV the savings would be approximately Rs. 1298.00 and Rs. 295.00 for a bike. Where am I getting with all this? Imagine how many vehicles are stranded for 2 minutes or less at a signal in Mumbai without any congestion. And now imagine the number of vehicles in the entire city of Mumbai. A research conducted in 2007 in Pune showed that the city wastes Rs. 34 CRORE that is Rs. 340 MILLION for people living outside India just by fuel wasted in idling. These figures pertain only to vehicles caught in minor traffic waiting at a signal for 2 minutes.
See it for yourself, here's the link:
http://pune360.com/Editorial/2007/10/31/an-idle-threat/
Cars idling in Delhi burn around 1000 CRORES of fuel a year. That is One followed by TEN freaking zeros!!!!!! And that's just ONE metro in India. The amount of idling caused in traffic jams is unimaginable in a city like Mumbai. Now calculate all the three zones, Western, Central and Harbour. And how many metros are there in our entire nation? You can calculate the harm that is being done to both, our environment
and our economy.

You have the answer for yourself whether to idle away literally or be responsible person towards the society and turn off the keys. I'm literally getting 25 extra kilometers on my bike because I have chosen not to idle at signals or in traffic. You too can make a positive difference to the environment without any extra effort or without giving up on anything and save money while doing that too. So next time you are caught in a jam remember to turn off the engine.
People who think likewise:
http://www.pca.state.mn.us/oea/ee/noidle.cfm
http://www.cleanwateraction.org/njef/campaigns-noidling.html
http://www.zerostart.com/power/no_idle_technology.asp
http://www.airwatchnorthwest.org/wa/NO_IDLE/index.asp
Delhi idling research article in the Times of India