What I do is back off the gas when I see the red light. If it is not chainging I easily pump the brakes and slow down before I get there so I don't have to come to a complete stop. Sometimes I do have to stop, but sometimes I can maintain at least some speed and not have to come to a complete stop. I don't know why, but I hate to come to a complete stop if I don't have to. There's not too much traffic around here anyway so I guess I am just not used to stopping all the time unless I am driving through town at the wrong time of day.
I don't practice any outlandish fuel economy tactics and I just leave the tranny in drive as that's what I have an A/T for.....so I don't have to shift. I guess I am just "shiftless"......
I don't know if this is the right way but it is the way I do it.
Usually i am going 5 to 10 under the speed limit to start with, when i see a light change i look to see how many lights and how far apart they are. In my 5 speed i just down-shift and this puts me into dfco. I try to keep the best momentum i can until i have to stop. There is usually a big gap between the car in front of me to my car so i have time and distance to do what ever is best. On on ramps with a lot of cars ahead of me to the light i just creep to the light at a slow speed and never stop. If you watch, truck drivers do this all the time.
I let my foot completely off the gas if there is a chance I will not catch the light green. In some cases that timing begins over half a mile before I reach the light, comes from driving the same exact route many times.
What you want is the highest speed possible when the traffic is moving away from the light, all else is irrelevant with one exception.
The exception is if you can not manage to keep moving through the intersection at least take the most time practical to reach the intersection. Doing this with DFCO means you use no fuel.
I might downshift from 5th to 1st under certain circumstances, as well as running the AC compressor to increase the deceleration, but only when I know I will not move through the intersection without stopping completely.
I also use the same philosophy at stop signs. You know you have to stop, so time your downshifting and DFCO so when you get to the stop sigh there are no cars in front of you if possible. Same thing applies to right turns on red lights.
AC use while in DFCO is free AC, as long as you do not delay your moving through the intersection, which means you have wasted your inertia.
I have driven through 23 lights in 16 miles with less than 90 seconds of engine idling total. That is the best measurement of you skill.
So what I am wondering is how big of a penalty in MPG does it cost to come to a complete stop?
I think that I've read somewhere that it takes 20% more energy to get a car rolling again than if you can just barely keep it rolling. When I see a red light I let off of the gas and coast for a while unless I am nearly to it then I'll apply the brakes lightly and try to keep up as much momentum as possible. The closer I get the more pressure I apply to the brakes if it hasn't turned green.