Hi. this is my first post. I will be picking up my Prius this week or next and can't wait. Try filling this out with your other car or the last car you owned before the Prius. Then try it with the Prius. I saw my numbers drop 40%. Not overly surprising, however a good way to gage just how much the environmental benefits can be for this car. try it out. thanks http://www.climatecrisis.net/takeaction/carboncalculator/ If you are in Canada like me, just select the nearest state to you.