BMW is stopping the engine on their new cars when the car stops. The European urban driving cycle test requires twelve stops of fifteen seconds over a 4.3 mile distance. I read one paper by BMW which said their system save 8% of fuel consumption in that test (or was it 8% better mileage?). But I can't find it again; all I can find is stuff that says it "reduces fuel consumption and emmissioins".
In case you're wondering, BMW didn't invent the system they're using, Bosch did. The starter motor mfr.
Yes if you're just racing from one light to the next like all the rest of the drivers and then by the time you've come to a complete stop you finally turn the engine off you might as well not even waste your time.
The best way to conserve fuel is first drive without brakes, that is, to coast to a complete stop by predicting lights and what have you... Then once you got that down what you do is right around the time you get your first clue that most likely you'll have to stop right then you put the trans in neutral and turn the engine off and coast in all the rest of the way.
Now what you've got is a good 30-45 seconds coast and EOC time, maybe it's only 20-30 seconds but I think 30-45 and sometimes even a minute or longer is possible... That's on TOP of coasting all the way to a stop for the final however many feet it takes to do so, so you could say when you can stop your car at a light in the right position without ever touching your brakes that's when you got it down to an art.
That's how it's really done, it is not at all unusual to coast 1/10th to 1/4 of a mile up to the light with the engine already off, brakes should not be needed thou during practice the power left in the lines is good for 1 maybe 2 applications (so use it wisely).
A FE gauge should be standard equipment in every vehicle.
my spin on this thread is : approach stops as tho you have no brakes, but don't shut the engine off ..PUT IT IN NEUTRAL an coast .. during this "coast" time you are getting 50, 70 even 100 mpg!! but you need the engine running for assisted steering ,brakes , signals ... etc!!
another benefit is that your brakes will last MUCH longer .. i know a guy that drove his full sized station wagon for almost 200000 miles and did not replace any brake parts at all ... and it was NOT over the road miles!! he drove a block ahead of where his car was .... like a jet pilot has to do.. dddon
When I lived in Germany, I found out that it was against the law to let your engine idle for longer than 5 minutes. I found this interesting because Germany had much lower emission standards than the US EPA. I believe that cars sold in Japan, California, and Mexico City have the most strict emission standards. Soon my city, Dallas, will be in that category! I'm not really too concerned with emissions or the greenhouse effect. I recycle aluminum and try to increase my MPG's just to help out my wallet!
Soon, (maybe very damn soon) saving gas, being efficient, recycling and being "environmental" will have more to do with survival than it will have to do with simply being responsible (like the Germans) or "saving" the planet. What I don't understand is why suburbanite McMansion owners are so broke and irresponsible that they can't afford to make their homes, cars and lives zero energy before they are forced to.