down hill coasting

[stevedebi]

I believe the Jetta Hybrid e-golf allows the driver to select the amount of regenerative braking to apply when coasting in gear ( 3 positions IIRC) Maybe Ford will implement this on its next generation. It would be nice to have one position to be no regenerative braking or at least very little regenerative braking (maybe just offset the HVB drain and no charging of the HVB.).

 

Early on I used neutral going down hills on the interstates until one time I forgot I was in neutral and tried to accelerate going back up the hill with traffic on my tail. I quit using it.

 

Edit: it's the e-golf not the Jetta Hybrid:

I'm not sure I see the point. Of course, the C-Max has two modes, hill mode and "L".  I don't think having three is that useful in general.

[plus 3 golfer]

I'm not sure I see the point. Of course, the C-Max has two modes, hill mode and "L".  I don't think having three is that useful in general.

 

I agree in general (not that useful to most people).   Ford says that the regenerative braking simulates conventional engine braking when taking foot off the accelerator not that simulating engine braking is the "most efficient" thing to do. It's likely many would not adapt quickly to something different from normal engine braking and "complain" :)  I would rather have complete control over regeneration when I take my foot off the accelerator with the opportunity to optimize FE.

 

The mode that appears to be most advantageous to me is coasting with no regeneration (legally :)).  I would think that in cruising on highways with rolling hills, one would save energy by coasting with no regeneration vs coasting with normal "engine braking" regeneration.  The only way to coast now with no regeneration is shifting into neutral.  How many times does one back off the accelerator when cresting a hill and then have to reapply the throttle before reaching the bottom.  If speed becomes a problem with coasting with no generation, one can control the speed with slight braking or even bumping the selector back to "normal" or "maximum" regeneration.  The benefit gets back to added aero losses (coasting in neutral vs in gear) vs the regeneration penalty which is IMO more than most believe it is.

Edited December 21, 2015 by Plus 3 Golfer

[ptjones]

Plus 3 Golfer" The benefit gets back to added aero losses (coasting in neutral vs in gear) vs the regeneration penalty which is IMO more than most believe it is."  I agree with you on this.  I will keep trying this when it's convenient  It takes to much effort to do it all the time.

 

Are you trying P&G in neutral or something else (fbov suggestion)? :)

Going down the hills in Neutral, EV on flats and ICE up the hills, Basically P&G :)

 

Paul

[BIG ROCCO]

Took the words right out of my keyboard, Steve.  There's a little mom-and-pop convenience store two blocks from my house.  Every time I go in there I could EASILY pocket a candy bar and get away with it.  Does that make it OK to steal candy bars?  Seriously, Rocco..........

 

Personally I couldn't care less if you drive down hills in neutral while texting your wife and eating a cheeseburger.  Couldn't care less.  But since we're on a forum and you're proposing dangerous advice to members, I'll weigh in with my two cents. 

OK, so I think you are saying that you would not do something that you consider morally wrong (theft, murder, embezzlement, adultery) even if you knew you would not be caught or punished...and I agree with you about that.

 

If there is a law that I do not embrace, but which harms no one else, yet which. if broken, I would likely be caught and punished - that's a law I may or may not follow (speeding, overtime parking).

 

If it's a law I don't agree with, with little likelihood of being caught/punished, and it's not a law I want to follow (voluntarily paying sales tax for internet purchases) - that's a law I will likely agnore.

 

 

I don't think I ever proposed any advice to anyone - I was just offering, for the discussion, what I do and that I feel it is more efficient, under certain circumstances, to use the momentum of the car directly, rather than convert the momentum to electrical energy and then back to forward motion.  I never brought 

 

I don't text while I drive - in fact, I hardly text at all.  But I was eating a Sausage Muffin with Egg and drinking coffee on the way to work today, however, it was after, not during, the coasting down the hill part of my commute.

[BIG ROCCO]

Plus 3 Golfer" The benefit gets back to added aero losses (coasting in neutral vs in gear) vs the regeneration penalty which is IMO more than most believe it is."  I agree with you on this.  I will keep trying this when it's convenient  It takes to much effort to do it all the time.

 

Going down the hills in Neutral, EV on flats and ICE up the hills, Basically P&G :)

 

Paul

 

There are sometimes long downhill slopes where the slope is gradual enough that I would need to use EV just to maintain speed, but which I can coast in Neutral and maintain or slightly gain speed, within safe limits; these slopes then level off or turn into an uphill slope - that is where I like to use N...but I am not proposing that anyone else do that, especially of they are morally, legally, or logically opposed to the idea.  I'm sure I spend <1% of my driving time coasting in N - I only mentioned it as what I consider to be the most efficient way to recapture the forward momentum of the vehicle, with friction brakes at the other end of the spectrum.  I do not spend my time constantly shifting from D to N...although I think I've read that in the Shell Eco Marathons, the drivers accelerate up to 20 or 30MPH, then shift to Neutral and actually turn the engine off and coast down to ~10 MPH before restarting the engine and accelerating again.  No, I would not advocate doing that on any public road.

[obob]

FYI

 

"The actual laws on "coasting" are not about putting the car in neutral, but actually shutting the engine off. In the 60s and 70s people would "coast" down hills with the engine off to save gas. Naturally, no engine power means no power steering, no power brakes, and a lot of accidents were being caused from this, so they outlawed this. Some states have laws about putting it in neutral or disengaging the clutch as well, but MA does not prohibit engine-on coasting in neutral. FL, OR, NM, CT, VA, RI all have no-coasting laws even with the engine on."

 

from https://answers.yahoo.com/question/index?qid=20130515042608AAvRyeP

Edited December 23, 2015 by obob

[BIG ROCCO]

FYI

 

"The actual laws on "coasting" are not about putting the car in neutral, but actually shutting the engine off. In the 60s and 70s people would "coast" down hills with the engine off to save gas. Naturally, no engine power means no power steering, no power brakes, and a lot of accidents were being caused from this, so they outlawed this. Some states have laws about putting it in neutral or disengaging the clutch as well, but MA does not prohibit engine-on coasting in neutral. FL, OR, NM, CT, VA, RI all have no-coasting laws even with the engine on."

 

from https://answers.yahoo.com/question/index?qid=20130515042608AAvRyeP

Thank you for that.  It's interesting that MA is mentioned, because that is where I grew up and first learned about coasting in N (with the engine on) to save gas.  Yes, I think coasting in a regular car with the engine off is dangerous (of course we all do that all day long in our CMs, but that is different).  Also, from a wear and tear perspective, I believe most automatic transmissions can be damaged in the long run, by repeatedly turning the engine off and coasting, as this will result in the input shaft to the oil pump not rotating and therefore no transmission fluid circulating to lubricate the bearing and gears.  Actually, I think one of the issues with early CMs is with premature transmission bearing or bushing wear, caused by lack of adequate lubrication in EV mode.  I think I read that the Energi has a supplemental electric trans oil pump to address that issue - I'm not sure what the fix was for regular CMs

[hybridbear]

I believe the Jetta Hybrid e-golf allows the driver to select the amount of regenerative braking to apply when coasting in gear ( 3 positions IIRC) Maybe Ford will implement this on its next generation. It would be nice to have one position to be no regenerative braking or at least very little regenerative braking (maybe just offset the HVB drain and no charging of the HVB.)

The Kia Soul EV & Mercedes B Class Electric Drive also have this feature. Doesn't the new Volt offer something like this too?

[ptjones]

I took my Wife's 2013 ECO-BOOST Explorer back to Flagstaff, AZ and got back yesterday( Terrible Driving Conditions, but the front wheel drive Explorer did great!). I tried out the shifting to Neutral while going down hill and works quite well when you can use it. It is probably worth 2-4mpg with the Explorer.  Also drive technique makes about 3-4mpg when comparing Prius Daughter and myself. LOL   :) 

 

Paul 

[Redshift]

Thank you for that.  It's interesting that MA is mentioned, because that is where I grew up and first learned about coasting in N (with the engine on) to save gas.  Yes, I think coasting in a regular car with the engine off is dangerous (of course we all do that all day long in our CMs, but that is different).  Also, from a wear and tear perspective, I believe most automatic transmissions can be damaged in the long run, by repeatedly turning the engine off and coasting, as this will result in the input shaft to the oil pump not rotating and therefore no transmission fluid circulating to lubricate the bearing and gears.  Actually, I think one of the issues with early CMs is with premature transmission bearing or bushing wear, caused by lack of adequate lubrication in EV mode.  I think I read that the Energi has a supplemental electric trans oil pump to address that issue - I'm not sure what the fix was for regular CMs

With a fuel injected car, it doesn't save any gas when coasting downhill in neutral because the computer has to keep the engine running, thus using gas. All modern fuel injection systems turn the gas flow completely off when coasting in gear. The forward momentum keeps the engine turning with no gas use at all. So driving in neutral uses more gas.

[raadsel]

With a fuel injected car, it doesn't save any gas when coasting downhill in neutral because the computer has to keep the engine running, thus using gas. All modern fuel injection systems turn the gas flow completely off when coasting in gear. The forward momentum keeps the engine turning with no gas use at all. So driving in neutral uses more gas.

 

While this would be true of conventional cars with a fuel injected engine, it isn't true of a hybrid -- so the oil pump not turning could be an issue on a long, gradual hill. 

[Redshift]

While this would be true of conventional cars with a fuel injected engine, it isn't true of a hybrid -- so the oil pump not turning could be an issue on a long, gradual hill. 

That is logical except that driving out of the mountains, my C-Max used the ICE constantly to help slow the car, even after the big battery was completely full.

[plus 3 golfer]

That is logical except that driving out of the mountains, my C-Max used the ICE constantly to help slow the car, even after the big battery was completely full.

That's because the HVB was full ;) and regenerative braking (MG2 - the traction motor acting as a generator putting load on the car) could no longer be used to simulate "engine" braking (ICE then spins for engine braking) and / or you used grade assist to maintain speed and grade assist couldn't maintain speed unless it engaged ICE.  Engine RPM can be very high when using grade assist.  I use it all the time.  Fuel will not be injected into the cylinders in these cases.  

Edited December 30, 2015 by Plus 3 Golfer

[ptjones]

With a fuel injected car, it doesn't save any gas when coasting downhill in neutral because the computer has to keep the engine running, thus using gas. All modern fuel injection systems turn the gas flow completely off when coasting in gear. The forward momentum keeps the engine turning with no gas use at all. So driving in neutral uses more gas.

My Testing of My Wife's 2013 ECO Boost  4cyl. Explorer w/auto trans doesn't support your statement. ;) I don't see how an ICE can stop without the vehicle stopping with an auto trans. At 70 mph I'm turning 2K rpm in neutral or Drive going down hill, 1k rpm at 40 mph in neutral or Drive. On my trip back from AZ I filled up outside of Birmingham,AL at about 100 mi. I remembered to use neutral coasting. I was getting 24.5mpg and 100mi. later I was up to 28mpg.  I had the same experience driving up to Smyrna from Newnan going out on my trip. When I get back my regular ScanGaugeII from friend I will put it on the Explorer to get more info. :) 

 

Paul 

[stevedebi]

My Testing of My Wife's 2013 ECO Boost  4cyl. Explorer w/auto trans doesn't support your statement. ;) I don't see how an ICE can stop without the vehicle stopping with an auto trans. At 70 mph I'm turning 2K rpm in neutral or Drive going down hill, 1k rpm at 40 mph in neutral or Drive. On my trip back from AZ I filled up outside of Birmingham,AL at about 100 mi. I remembered to use neutral coasting. I was getting 24.5mpg and 100mi. later I was up to 28mpg.  I had the same experience driving up to Smyrna from Newnan going out on my trip. When I get back my regular ScanGaugeII from friend I will put it on the Explorer to get more info. :)

 

Paul 

The ICE doesn't stop; it continues to run. It just doesn't burn any fuel.

[ptjones]

The ICE doesn't stop; it continues to run. It just doesn't burn any fuel.

I can watch fuel flow with the ScanGaugeII when I get it plugged in. :)

 

Paul

[raadsel]

That is logical except that driving out of the mountains, my C-Max used the ICE constantly to help slow the car, even after the big battery was completely full.

 

Plus 3 Golfer gave the answer; when the battery is full going down a hill it will use the ICE, but have the fuel cut off, as an engine brake.

[stevedebi]

I can watch fuel flow with the ScanGaugeII when I get it plugged in. :)

 

Paul

Well, report back for sure! But my FEH certainly did this, and there is no reason to burn gas when going downhill, assuming the downhill is steep enough to require engine breaking. I have a SGII, but have not plugged it into my Energi yet.

[ptjones]

Well, report back for sure! But my FEH certainly did this, and there is no reason to burn gas when going downhill, assuming the downhill is steep enough to require engine breaking. I have a SGII, but have not plugged it into my Energi yet.

Why? It only takes a minute to do. CMAX has two plugs, one under the steering column is the easiest to get to and then stick wire between dash and inside wall by door jam. Leave extra wire on top of dash. :) 

 

Paul 

[stevedebi]

Why? It only takes a minute to do. CMAX has two plugs, one under the steering column is the easiest to get to and then stick wire between dash and inside wall by door jam. Leave extra wire on top of dash. :)

 

Paul 

Paul,

It is not for lack of knowledge, I just don't feel the need with the C-Max Energi like I did with my Escape Hybrid. I get sufficient information from the existing displays.

 

Also, for the Energi at least, using the OBD port interferes with the health functionality.

[ptjones]

Paul,

It is not for lack of knowledge, I just don't feel the need with the C-Max Energi like I did with my Escape Hybrid. I get sufficient information from the existing displays.

 

Also, for the Energi at least, using the OBD port interferes with the health functionality.

I'm not so sure on my CMAX Hybrid, FORD did the ICE Smog update and it didn't appear that they unplugged my ScanGaugeII. I know when I had the ScanGaugeII and another Blue Tooth OBD monitor plugged in at the same time that it sometimes caused problems. ;) Never use vehicle health report and my MPG's keep going up. :)

 

Paul 

[SnowStorm]

Paul, are you sure you don't have a kindly practical joker around that keeps slipping just a little more gas into your tank after each fill up?  Many years ago when "small" cars first came out I heard of such a thing actually happening!  The guy was ecstatic with his MPG.

[djc]

Doesn't Engineering Test Mode show instantaneous fuel use?

[ptjones]

Paul, are you sure you don't have a kindly practical joker around that keeps slipping just a little more gas into your tank after each fill up?  Many years ago when "small" cars first came out I heard of such a thing actually happening!  The guy was ecstatic with his MPG.

It sure seems like it. LOL  But the Smart Gauge would show more gallons being used. Yesterdays fillup had Smart Gauge at 12.8 and actual was 13.85 gal.  I'm getting pretty good at coasting now. Last night I did 4 short trips for a total of 37.6 mi. and averaged 54mpg with temps from 32-36*F.  Amazing. :)

 

 

Doesn't Engineering Test Mode show instantaneous fuel use?

Empower Display shows instantaneous FE and Engineering Test Mode not practicable to use all the time.  

 

Paul,

It is not for lack of knowledge, I just don't feel the need with the C-Max Energi like I did with my Escape Hybrid. I get sufficient information from the existing displays.

 

Also, for the Energi at least, using the OBD port interferes with the health functionality.

IMO The most important gauge for FE is an accurate WT gauge which the CMAX doesn't have unless you go into the engineering mode. You get the Best FE with WT above 202*F. I use IT, WT, TFT and SOC on my ScanGaugeII.  In my old pic I have instantaneous mpg.   :)

Edited January 5, 2016 by ptjones

[stevedebi]

It sure seems like it. LOL  But the Smart Gauge would show more gallons being used. Yesterdays fillup had Smart Gauge at 12.8 and actual was 13.85 gal.  I'm getting pretty good at coasting now. Last night I did 4 short trips for a total of 37.6 mi. and averaged 54mpg with temps from 32-36*F.  Amazing. :)

 

 

Empower Display shows instantaneous FE and Engineering Test Mode not practicable to use all the time.  

 

IMO The most important gauge for FE is an accurate WT gauge which the CMAX doesn't have unless you go into the engineering mode. You get the Best FE with WT above 202*F. I use IT, WT, TFT and SOC on my ScanGaugeII.  In my old pic I have instantaneous mpg.   :)

Just a note for the newbees, there is no water temperature sensor. That is an estimated temp from the cylinder head temp guage. Ford did this on the Escape hybrid as well. I have no idea why they didn't just put in a sensor for water temp.

 

The SG II and the engineering test mode displays report the inferred temperature.