so a lot of extreme hypermiliers say they turn their engines off at traffic lights, but doesnt it use a lot of fuel to turn the engine on again? What is the amount of time needed so that it is more efficient to turn the engine off?

 

The EPA actually recommends it if you know you'll be at the light longer then 30 seconds. IIR though, the gas used from turning the car back on is the equivalent of running the car for 10 seconds.

The other side of the debate is that the wear and tear to other parts, such as the starter, negates any savings that would have come from turning off the engine at lights.

Personally, I'll do it sometimes, but only in areas that I'm extremely familiar with.

 

Equivalent to 10 seconds at idle right? Silly maybe...but worth asking...
If so thats really interesting to know, if you dont mind, where did you happen to find this info? It's very useful to be able to quantify that consumption.

 

Best times to turn engine off IMO:
-at train crossings
-Sonic Drive-Ins
-sitting in the parking lot listening to the rest of a song before getting out

 

Correct. I got the info on another forum when someone posted a similar question. Someone had posted a link to the EPA that it. I stand corrected though, it looks like 5 seconds.

Frequent Questions - Idling Reduction - SmartWay Transport Partnership - EPA

 

ive heard the 10 seconds thing too but not from here i think it was a commercial or something-
but i will never turn my car off while driving- with my luck it wont turn back on-

 

Can't tell you the gas used to turn it on, but for sure. The Scane Gauge is no help with that at all. What I can say from data:

1. About .25GPH at idle warmed up Fit
2. My 26 mile commute avg MPG will drop about a tenth of a mpg ever 5 to 10 sec when I sit at idle.
3. Math: at 65mph and 43mpg that around 1.5GPH

I have not timed any of my stops (I need to get a watch) lol ,but I know the long lights and if I'm rolling into one that just cycled I kill her. Sometime I kill the eng and roll in dead.

here's a tip
If you don't have a traffic issue, look waaaaaay ahead (like a 1/4 mile or more) and lift and coast and time it so you hit them green

 

Thanks
Much appreciated

 

It would be nice to know who much fuel a warm fit uses to restart.

 

I go by the 10 second rule. I'd never turn my car off at a light though, that's just asking for trouble. Generally I'll just go inside instead of being lazy and staying in my car for a drive-through or anything drive-up. Gives me some excercise and saves gas too!

 

yep do the same, but I kill mine at any light that is more than 1 min. I have gotten to the point I'll kill her and coast in. Of the extreme measures, I feel this has the least neg effects on the car. I think the starter can take it.

 

Be carefull with that coasting, you'll only have a limited amount of braking before the pressure is out of the brake lines. I did coasting a few times with the car off and almost crashed when my brakes stopped working lol.

 

I think we need to get the Mythbusters on this one!

 

i was told it once that it was illegal to have your car out of gear or something to that measure at a light because if there was an accident or something you couldn't get out of the way in time

 

Maybe it's just me, but i don't understand what you could possibly gain from turning off your car for as little as 15-20 seconds at a time.

Of Course my car gets anywhere from 12-22mpg (depending on how much i beat it), and i have to run Premium at ALL times, but still...

congrats! you saved .000000000000000000000215 gallons of gas this year, and it only cost you:

1) a starter
2) an ignition switch
3) 2 very expensive keys
4) $3300 towards insurance (because you go creamed by a truck that hit you just enough to set off your airbags)
5) an engine knock due to dry cranking the motor every 3 blocks
6) 3 sets of fouled spark plugs
7) 4 lawsuits, 2 broken noses, and a fractured jaw (all due to road raged drivers waiting for you to start your car back up)




...not trying to be rude, but seriously there is NOT many better times to leave your car running than at a red light. If you are worried about the environment, I let my car warm up for 10min before i even leave the house.

 

Actually where i live, i can hit a 5 minute light, also some people live near railroad crossings where you can sit for over 20 min.

 

: rotfl:

Please elaborate j/k

 

lol.

I am just saying If you are that concerned about the gas. buy a hybrid that turns off all by itself.

 

but there arent any hybrids that are as fun as the fit. Thats why i got the fit, excellent gas milage and fun. Plus unless you get an insight there arent any stick hybrids

 

So you want to be able to bang gears in a high revving Vtec , but you want to turn off the car at red lights?

...I don't follow.