Is it ok to brake after coasting towards a stop?

[PaleMelanesian]

Originally Posted by XYZ

Absolutely true. It depends on the design of the transmission, how rudimentary or advanced it is, and how the electronic programs (on more recent years) are monitoring and controlling what it does. Unfortunately, there is no practical way to discover all the subtleties of an automatic transmission until after you have purchased a vehicle and experiment with driving it.

I also agree that it is confusing to call coasting while in Drive "coasting" at all. But compared to driving with your foot constantly on the gas pedal, it probably is somewhat more beneficial.

indeed.

In the case of my Odyssey, it's a programming issue. They even call it a feature. In certain uphill and downhill conditions, it even holds it in 4th gear instead of 5th. Drives me crazy!

You know you're an ecomodder if...

[user removed]

Originally Posted by PaleMelanesian

In some cases, but not always. For example, Honda automatics will hold it in gear and engine-brake if you leave it in D. That's not coasting. When I drive the Odyssey, I'm constantly shifting D-N-D-N to get any real coasting.

Some vehicles' transmissions are programmed to go into a nearly neutral state automatically, like what you're describing. GM trucks come to mind from my experience.

Precisely what I do. I had a Riviera that would coast the same in gear as neutral. My guess would be they unlock the converter while staying in top gear, which also allows you to reengage the gears smoothly with maybe a slight throttle blip when reengaging at high speeds.

Coasting in neutral can net you periods of 100+MPG, never avoid them. The Sentra will shift to neutral and back to drive without having to even touch a button.

regards
Mech

[SilverCrown9701]

Hey everyone,

So I tried coasting in Neutral yesterday on all of the areas where I leave it in Drive when I release the gas pedal. A few things I monitored...

-I coast just as far in neutral as I do in drive. It's no further. It slows me down at the same rate. I don't have any steep declines in my area. Just flat to rolling hill terrain.

-My UltraGauge shows 999.9 MPG while in Drive from 50 MPH down to 20 MPH. In Neutral, it shows 70-100 MPG at 50 MPH then declines from there as my speed drops. My Instantaneous Gallons Per Hour is .35 GPH while in Drive. It is .6 GPH while in Neutral. This is with no A/C on, nothing.

-When I shift from Drive to Neutral at 40-50 MPH, I feel a slight jerk and lurch. The sane happens when I reengage the transmission.



Based on this observation, it would seem that coasting in drive is more beneficial for my particular car than neutral. Is this strange? My UltraGauge is not calibrated.


One more note: On my last tank trip, I achieved my 37 MPG average using coasting in Drive. However, I also used DWL and no A/C as well.

[MetroMPG]

Originally Posted by SilverCrown9701

-I coast just as far in neutral as I do in drive. It's no further. It slows me down at the same rate. I don't have any steep declines in my area. Just flat to rolling hill terrain.

If that's the case, I'd just leave 'er in D.

[SilverCrown9701]

My car must be the black sheep. Unless my UG is off...

[digital rules]

Are you using the 6 or 8 gauge display on the Ultraguage? The 8 gauge display doesn't always show DFCO, so I use 6 gauge.

Also, did you dial in the correct injector cutoff value in the menu? It's based on engine size & the intructions are in the manual, but don't have it available right now.

[Xist]

You describe having DFCO while in neutral, which does not sound possible. I am not doubting you regarding the 0.6 GPH in idle, but my Forester only uses 0.25.

It really depends on what you are doing. If you are a light-timing genius, you should never need to coast in-gear or use your brakes, while DCFO uses no gas and neutral uses a little, how much do you use accelerating back up to speed?

If you have a stop sign, would you prefer to drive at your city mileage and then DFCO, or coast in neutral for a much longer distance? That is, unless you have people behind you. I always do, all hours of day and night.

If you have a very gradual hill and you can roughly maintain your speed in neutral, that makes more sense than keeping it in drive and getting 40-45 MPG, because you could get 91.67 at 55 MPH.

If you have a steeper hill, you need to stay in-gear for engine braking, and sometimes you need to downshift.

My ex-girlfriend complained that the transmission was rough shifting between neutral and drive and then she replaced her transmission mounts. She is my ex-girlfriend, I try to avoid her and definitely not to help her think through her problems anymore, but I did try to explain that some repairs are not worth the money, and how terrible an idea it is to pay for things when it puts your account in overdraft.

[SilverCrown9701]

Originally Posted by digital rules

Are you using the 6 or 8 gauge display on the Ultraguage? The 8 gauge display doesn't always show DFCO, so I use 6 gauge.

Also, did you dial in the correct injector cutoff value in the menu? It's based on engine size & the intructions are in the manual, but don't have it available right now.

I am using the 6 Gauge display. I have Instantaneous MPG and Instantaneous Gallons Per Hour displayed. I have the UltraGauge EM.


Yes I have set the DFCO according to my engine size.

[Xist]

Originally Posted by digital rules

Also, did you dial in the correct injector cutoff value in the menu? It's based on engine size & the intructions are in the manual, but don't have it available right now.

UltraGauge OBDII Scan Tool User Manuals

[SilverCrown9701]

Originally Posted by Xist

You describe having DFCO while in neutral, which does not sound possible. I am not doubting you regarding the 0.6 GPH in idle, but my Forester only uses 0.25.

It really depends on what you are doing. If you are a light-timing genius, you should never need to coast in-gear or use your brakes, while DCFO uses no gas and neutral uses a little, how much do you use accelerating back up to speed?

If you have a stop sign, would you prefer to drive at your city mileage and then DFCO, or coast in neutral for a much longer distance? That is, unless you have people behind you. I always do, all hours of day and night.

If you have a very gradual hill and you can roughly maintain your speed in neutral, that makes more sense than keeping it in drive and getting 40-45 MPG, because you could get 91.67 at 55 MPH.

If you have a steeper hill, you need to stay in-gear for engine braking, and sometimes you need to downshift.

My ex-girlfriend complained that the transmission was rough shifting between neutral and drive and then she replaced her transmission mounts. She is my ex-girlfriend, I try to avoid her and definitely not to help her think through her problems anymore, but I did try to explain that some repairs are not worth the money, and how terrible an idea it is to pay for things when it puts your account in overdraft.

No, I never said I had DFCO while in Neutral. It's only in Drive.
My apologies, I meant to type .25 GPH, not .35 GPH...(I'm using a mobile phone to type so my fingers keep missing the correct buttons.)

Whether I use Neutral or Drive to slow down to stop, I will still have to get back up to speed, so I am at a slight loss either way.


I guess I will need to try one tank on neutral coasting alone and another on DFCO. I just really don't want to risk having to replace my transmission for $3,000+...