There are folks in this world who will drive 20 miles to S.C. and then back to save 10 cents a gallon. On a car with a 13 gallon tank and gets 30 mpg, you will save $1.30 on the tank and spend $5.33 worth of gas @$4.00 a gallon. Net loss of $4.03.
Today in the drive thru a lady cut her car off every time she came to stop.. would wait about a minute and move forward. Every time you stop your engine, upon restart your car's fuel injection will burn about the equivalent in fuel of 4 minutes of idling. We spent 5 minutes in the line, she started the car 3 times burning 12 minutes worth of fuel. Net loss of 7 minutes of idle fuel.