It has been 5 months since changing over from a truck to our first Toyota Prius.  We have put 5,800 miles on the car and are averaging 44 miles per gallon.  Our gas bill has dropped from $1,200 per month to $120 per month.  That is right, 90% drop.  Part of that has to do with the drop in gas but the miles per gallon went from 14 to 47 mpg.  We just purchased our second Prius.  Now look out for a dark gray and red Prius checking up on the jobs.