Idle time before killing the engine for FE.

[VetteOwner]

Originally Posted by DRW

In downtown San Francisco they've installed new crosswallk signals that show an actual countdown so you know how much time is left before the signal changes. It's very helpfull.

haha same here. i dunno if its for the pedestrians or the drivers...

[JanGeo]

At an idle fuel use of .1gph it comes out to $0.30 an hour at $3 a gallon so for 60 seconds it burns 0.5 cents of gas . . . I think I will just let the engine run . . . thank you very much!

[DRW]

You're lucky, my car uses a little more fuel than that. When my engine is fully warmed at idle it uses .35gph, fully warm and idling while moving(coasting in neutral) uses .41gph since the ecu raises idle slightly so there's enough power for power steering and brakes. When the coolant temp reads 65*F it uses .70 gph at idle and .78 gph idling while moving. This is why I like eoc when the motor is cold. My motor is a 2 liter 4 cylinder, which I consider a mid size engine among the members on this site. Factor in my cost of gas currently at $3.72/gallon and it adds up fast. I'm very happy to be getting 43mpg out of a 260HP sports car.

[thecheese429]

Originally Posted by brucepick

Yup, except it might be illegal, and will likely PO the drivers behind you if they have to wait for you to get going.

Sometimes I'll kill the engine at a light if A) it's daytime so headlights are off so others can't see that I'm restarting AND B) there is at least one car ahead of me at the light so I get advance notice that I need to start it up. ymmv.

go ahead and kill it if you don't have diesel.
if you're the first one in the light, you can see the signals most of the time. if you're not first in line, you still have time to start your engine because of the slow person in front of you.
If you're observant (like any good gassaver would be) then you can see when the light's about to change. here in texas at least, the hand for the crosswalk will start flashing for about 30 seconds and after that you'll see the light perpendicular to you become yellow for 7 seconds, then red and after one second of all red, you'll get the green.

I think that 38 seconds is even enough to start even a diesel chevette.

[jandree22]

Originally Posted by JanGeo

At an idle fuel use of .1gph it comes out to $0.30 an hour at $3 a gallon so for 60 seconds it burns 0.5 cents of gas . . . I think I will just let the engine run . . . thank you very much!

Agreed... when dropping off and picking up my wife/son from work/daycare, I?ll shut the engine off because it?s usually a minute or two. Traffic lights? That?s way too frequently for me to stress the starter and battery on my ?07 baby

[yi5hedr3]

Originally Posted by shblanchard

With regards to the drivers behind you:
I travel the same route commuting, so I got into the habit of watching the stoplights to the right of me, as well as the one in the left turn lane. Watching those gives me an idea of when my light is about to turn green, so I can restart the engine just before it turns. That will mean a few less ticked off drivers behind me...

Yep - that's what I do to. When the cross lights go yellow, I start the car. I shift from neutral to drive just a split second before I get the green. Works perfectly!!

[yi5hedr3]

Originally Posted by jandree22

Agreed... when dropping off and picking up my wife/son from work/daycare, I?ll shut the engine off because it?s usually a minute or two. Traffic lights? That?s way too frequently for me to stress the starter and battery on my ?07 baby

Yeh, I don't do every light, but I pretty much know which ones are horribly long, and I?ll shut down for those!!!

[jandree22]

Originally Posted by yi5hedr3

yeah, I don't do every light, but I pretty much know which ones are horribly long, and I?ll shut down for those!!!

Yeah, that's not as bad... there are definitely one or two in my area that I DREAD being caught up in on a fresh red, especially because they're usually ideal cruising strips of 45mph highway.

[JanGeo]

Ok here is a simple test - warm the car up and after driving say . . . a few miles you have a SG with a trip MPG reading of X.X mpg then stop for a minute and then take off again and finish a test route. Next time you turn the engine off and wait a minute then start it and finish the route and see the difference in the MPG for the trip. Difference will be the startup fuel consumption - remember you can just drive in a circle if you like and simply reset the trip MPG on the SG.

[Snax]

On my commute, I am often doing an EOC through one green light in anticipation of the red at the next intersection. When I anticipate it correctly, I don't even have to stop completely and just bump start to the one following that. I rarely shut it off after stopping, but do allot of EOCs to a stop.