Vehicle population in India rose from 2 crore in 1991 to about 10 crore in 2007 and by 2016, the number is expected to rise by whopping 4 times. Presently, the contribution of automotive sector to country's GDP growth is 5%, while by 2016, it is envisaged to be 10%. It has also been predicted that by, 2016, India will-emerge as 7th largest Car manufacturer, 2nd largest two-wheeler manufacturer and the largest three-wheeler & tractor manufacturer in the world. The increase in number of vehicles therefore undoubtedly will lead to increase in consumption of oil & gas, since almost all motorized vehicles in India run on oil & gas. India consumes almost 40-50% of .its petroleum products in transport sector. Burning of fossil fuel leads to another significant implication to the environment. Every kg of gas/oil burnt emits 3 kg of Carbon dioxide to the environment. India stands 5th in the world in C02 emission after US, China, Russia and Japan. Out of India's total contribution of 1100 MMT of C02 into the environment every year, a large chunk of 430 MMT is shared by fossil fuel alone. Petroleum Conservation Research Association (PCRA), under the Ministry of Petroleum & Natural Gas, has been taking constant endeavours in educating the masses on how critical is the aspect of Fuel Efficiency for Indian economy. PCRA has identified several user-friendly measures for efficient utilization of fuel in transport sector that offers the potential of considerable amount of saving in fuel consumption. These simple measures, if strictly adhered to, not only result into comprehensive savings of individual's monthly fuel bill, but also significantly contribute towards reduction in national crude oil import bill and most importantly protect our environment by reducing C02 emissions. PCRA, in association with Indian Institute of Petroleum (IIP), conducted a significant study titled "Studies on Passenger Cars for Fuel Efficiency at Different Speeds and Non-effective period for Idle-Stop" to find out the best fuel-economy speed range and the non-effective period for idle-stop based on fuel consumption for popular passenger cars of new generation. The test results revealed that the most fuel-economy speed for all these cars ranges between 45-50 KMPH. India being one of the fastest growing economies in the world, its energy consumption is sure to soar in the years to come, but our efforts need to be directed towards the most-efficient utilization of energy in all sectors. This undoubtedly would reduce the amount of C02 emitted and thereby leading to a safe and greener environment for our future generation. Simple adoption of good driving habits may therefore make significant impact into our environment. Drive the cars between 45-50 KMPH and switch-off the car engine at traffic red lights beyond 15 seconds. Act now for a better and greener tomorrow.