[Gregte]

Have any of you measured the difference in fuel mileage between shutting the engine off at stop lights or not shutting it off?

I have a 10 LED display in my vehicle that shows the relative amount of fuel being delivered to the engine at all times. I did the math, and made some educated guesses, and concluded that my vehicle is using about 1/5 the fuel at idle that is uses at 50 mph, normal driving.

Doing a little more math says that if I shut off my engine for 1 minute (average stop light) 10 times a day I will save about $1 a week if gas is $4/gal.

I weigh the $1/week against the presumed wear and tear on the starter as well as the inconvenience of re-starting the engine and possible safety concerns and I can't get too excited about it.

Again, have any of you measured the difference in fuel mileage between shutting the engine off at stop lights or not shutting it off?

EDIT: A small mistake in my earlier math. It would take me three and a half weeks to save $4 gas. This would be $1.14 per week. This is assuming (I did rough calculations) that my car would burn 1 gallon in 3.5 hours idling.

If your car burns twice that much in an hour of idling you would save $2.28/week assuming 10 one minute stoplights per day.