Re: How much gas does a car use when idling, how much used to start the engine?

Hi Stephen,

I have been told (but have not verified it), that it takes 1/4-1/2 teaspoon 
of fuel to start a car engine (more if the engine is cold).

As for idling, I can use my own car as an example.  My car has a computer 
which measures instantaneous fuel consumption.  Typically, it consumes 1.1 
L/h.  It's a 4-cylinder, '98 model, ie. fairly new, and fairly fuel 
efficient.  Older cars, and cars with larger engines would probably use 
slightly more fuel.  Also carburetted models tend to use more fuel than 
fuel injection models.

So, at 1.1 L/h, 4 minutes of idling at the train track would use about 73 
mL of fuel.  Compared with the teaspoon or so used for starting, it would 
seem a lot more worthwhile switching your engine off.

Hope this has helped,

Jonathan Feldman
University of Technology, Sydney