Is it ok to brake after coasting towards a stop?

[Xist]

Originally Posted by MetroMPG

Stopping the engine when the car is stopped is worth roughly 5-10% better fuel economy in city driving, which is why auto stop/start is now becoming common on new cars (including non-hybrids).

Whether you should do it or not is entirely up to you.

I believe that I read on here that starting the engine uses the equivalent of eight seconds of idling.

[RedDevil]

Originally Posted by Xist

My ex-girlfriend insisted that the car used less gas in neutral than park, but I told her that it was not worth wearing out the transmission to go from 0.27 GPH to 0.25 GPH for an average of a minute or less, when the car was rated 25 MPG. If you drive 55 MPH on the freeway (limit 65), you use 2.2 GPH.

My car uses just about 60% of the fuel when idling in N, foot on the brake, compared to idling in D, foot on the brake; even though it revs a bit higher, freed of the load.
That also makes it recharge the hybrid battery faster. So it does not only save me fuel then, it will also save me fuel later on.

Still I prefer AutoStop, not burning fuel at all now, even though it may need to compensate a bit later for the slight loss of charge.
I use less than 0.2 GPH idling in N. But then, I use about 0.4 GPH (1.5 l/h) at 38 mph. Sadly I need to go faster most of the time.

[cowmeat]

My advice is to coast it up to the light in neutral as quick as possible, and shut it down until you absolutely have to start it back up.

In the Black Widow, the very first hypermiling technique I ever employed was to simply shut it off at lights. I got an instant return of about 6 mpg on the tank! Then I was hooked!

Once your car is warmed up, it re-starts pretty easily, and unless your starter is an old p.o.s. you won't wear it out. Before I learned to bump start the Festiva, I would key start every time after EOC and P&G. I restarted that car literally thousands of times without killing anything

As far as coasting through stop signs, I never recommend anything like that. Hypermiling is a personal choice, but it shouldn't affect the other drivers you share the road with, unless you wanna give us all a bad name. 100% of my hypermiling is done without breaking any traffic laws (other than the Black Widow being off half the time) and without being a PITA to anybody around me.

[SilverCrown9701]

Originally Posted by MetroMPG

That's a good thing! If you have the time, and won't be annoying following drivers (who can't pass you), then start the neutral coast sooner. That'll save more fuel.

If you are *trying* to slow down faster than coasting in N, then using deceleration fuel cut-off in gear is more efficient than using the brakes. But coasting in N is generally more efficient than DFCO because you get off the accelerator (accel. or maintaining speed, burning the most gas) even sooner.

Also, your car only cuts fuel above a certain RPM, and possibly not at all in the lowest gears (your gauge may show you this). I recently drove a brand new Nissan 4-speed automatic that never cut fuel in 1st or 2nd gear.

I only know of one person who has worn out a starter while trying to save fuel, but he was shutting off at every single opportunity, including pulse & glide (automatic). Driving a Honda.

Stopping the engine when the car is stopped is worth roughly 5-10% better fuel economy in city driving, which is why auto stop/start is now becoming common on new cars (including non-hybrids).

Whether you should do it or not is entirely up to you.

I'm so glad to hear this. Finally, I don't feel insane or fretting anymore

[SilverCrown9701]

One more thing...Is it advisable to remove the spare tire and jack in my vehicle? It's a full size spare and equipment. Will I see any gains by removing it?

[SilverCrown9701]

Originally Posted by cowmeat

My advice is to coast it up to the light in neutral as quick as possible, and shut it down until you absolutely have to start it back up.

In the Black Widow, the very first hypermiling technique I ever employed was to simply shut it off at lights. I got an instant return of about 6 mpg on the tank! Then I was hooked!

Once your car is warmed up, it re-starts pretty easily, and unless your starter is an old p.o.s. you won't wear it out. Before I learned to bump start the Festiva, I would key start every time after EOC and P&G. I restarted that car literally thousands of times without killing anything

As far as coasting through stop signs, I never recommend anything like that. Hypermiling is a personal choice, but it shouldn't affect the other drivers you share the road with, unless you wanna give us all a bad name. 100% of my hypermiling is done without breaking any traffic laws (other than the Black Widow being off half the time) and without being a PITA to anybody around me.

Some of the traffic lights on my routes are no more than 8-10 seconds. Is that even enough time to shut down to see a change in FE?

[niky]

I'd just coast down to those lights. 30 seconds or more is worth it, depending on the car. 10 seconds is rather marginal. Pulse-and-glide between lights properly and you shouldn't even spend any time stopped.

The weight of the spare has an effect, but it's not much. I'd take it out if you were going to the racetrack. On the street, it's probably not going to make a noticeable difference.

[SilverCrown9701]

Originally Posted by niky

I'd just coast down to those lights. 30 seconds or more is worth it, depending on the car. 10 seconds is rather marginal. Pulse-and-glide between lights properly and you shouldn't even spend any time stopped.

The weight of the spare has an effect, but it's not much. I'd take it out if you were going to the racetrack. On the street, it's probably not going to make a noticeable difference.

By coast, do you mean in Drive or in Neutral?

I have an automatic, so I don't think pulse and glide is safe nor efficient for my vehicle.

[XYZ]

Originally Posted by SilverCrown9701

If I can safely "coast" through a stop sign at 15-20 MPH with nobody around then I will notice that lurch when I give it a certain amount of throttle but that's when it's in DRIVE, my guess is it's trying to up shift quicker??

Two comments: Sailing through a stop sign at 15-20 MPH may get you a summons someday. You might save 5 cents worth of fuel, but on the day there is a waiting cop who is stealthier than you that you didn't notice, it may not be worth the fine incurred.

No automatic transmission will be damaged by coasting in neutral to a stop or a "near stop". That means you can safely re-engage into drive in first gear, at under 10 MPH. Rev matching at higher speeds may or may not be detrimental. There is usually no way to tell with absolute certainty. You may not realize it until your transmission needs to be rebuilt. The amount of $ you saved on fuel in coasting will seem a pittance compared to the cost of an A/T rebuild.

[XYZ]

Originally Posted by SilverCrown9701

By coast, do you mean in Drive or in Neutral?

I have an automatic, so I don't think pulse and glide is safe nor efficient for my vehicle.

Pulse and glide with an A/T basically means getting it up to speed so as to get it into a higher gear, then taking your foot off the gas pedal completely, until you need to accelerate again. It amounts to "coasting" while still in "Drive".