• Automobiles are one of the main causes of carbon dioxide emissions into the atmosphere. They burn fossil fuels for energy, and their carbon dioxide emissions are released as exhaust. Cutting down on car energy use can help reduce the impact on the environment while saving the driver money by stretching his fuel further.
  
  

Defensive Driving

• Driving habits are one of the most important factors that determine car energy use. The more gas you give a vehicle by stepping down hard on the gas pedal, the more energy it will consume. Forcing a vehicle to accelerate quickly will use more energy than allowing it to get up to speed gradually, and slamming on the brakes wastes forward momentum. Slow acceleration and coasting to a stop instead of braking hard will help reduce gasoline consumption. Leave enough following room behind cars ahead of you so you don't have to brake constantly. Tailgating leads to lost energy.
  
  

Speed Limits

• Speed limits exist to keep drivers safe, but also to optimize car fuel economy. The optimal speed for many car engines to get the most gasoline mileage is around 55 or 60 mph. Exceeding these speeds on the freeway can lead to drastic reductions in fuel economy, because the engine goes into high RPMs and has to fight increasing wind resistance.
  
  

Weight

• The weight of a vehicle determines how much energy the engine must use to get it up to speed and keep it moving. When your car is loaded with five passengers and luggage, the fuel economy will be poor, but if you keep the car empty, your energy use will improve. It is a good idea to remove heavy items from your vehicle if you don't need to store them inside. Vehicles with removable seats can be lightened by taking the seats out and storing them somewhere safe.
  
  

Cruise Control

• Cruise control is a feature available on many cars that allows the vehicle to automatically keep going at a certain speed. Cruise control moderates speed so the driver does not need to constantly give the car a little extra gas and then let up on the pedal to maintain speed. Using cruise control eliminates human error, which can significantly reduce energy consumption.
  
  

Idling

• Idling occurs when your engine is running and is consuming energy but you have the brake pedal down so you aren't moving. The energy consumed while idling is considerably less than when you are moving, but there is usually no reason to keep the engine running if you are not going anywhere. If you need to idle for 30 seconds to a minute or longer before you can accelerate, shutting off the car can save fuel.