Turning off engine while at a stop light

When does it make sense to turn off the car engine while waiting for a traffic light?

There are one or two lights that I go thru a couple times a day that are very long waits. I can listen to a complete FM song – 2 to 3 minutes if I just miss it and have to wait for the complete cycle. I can see the pedestrian sign and watch it go thru the “walk”, “blinking don’t enter”, and then the solid “don’t walk” stage.

During this last stage, I know the opposite lights are yellow, and so I am about to get a green.

So if, as I get to the light, the cross pedestrian light is “walk”, I know I have a wait. I can turn off the engine, wait for the solid “don’t walk”, and then turn the engine on.

But am I saving anything?

I should be saving a little gas, but does it take more gas to re-start the engine than I’ve saved?

I know I’m polluting a little less, but does starting the car pollute more than just letting it idle for 2 minutes?


Your starter has so many “cycles” built into it. How you use those cycles is up to you…Will you save anything by turning off the engine at a stop light? Not enough to worry about…

I agree with Caddyman. You’re putting added wear on your starter assembly to save what in a protoge will be an amount of gas that’s too small to measure.