Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 11-04-2012, 07:21 AM   #11 (permalink)
GRU
Master EcoModder
 
GRU's Avatar
 
Join Date: Oct 2011
Location: Windsor ON Canada
Posts: 373

silver bullet - '00 Honda Civic
90 day: 34.41 mpg (US)
Thanks: 21
Thanked 36 Times in 31 Posts
If youre driving and all of a sudden you need to stop then leave it in gear but if you have a chance to coast to a light from a half mile away then put it in neutral because if you dont you will need to keep your foot on the gas pedal longer to get to that light

__________________

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 11-04-2012, 08:38 AM   #12 (permalink)
EcoModding Lurker
 
Join Date: Oct 2012
Location: muskoka
Posts: 80

Speedy Gonzales - '11 Ford Fiesta SES
Thanks: 7
Thanked 10 Times in 6 Posts
Quote:
Originally Posted by jamesqf View Post
Even if your engine has DFCO, it is still losing some energy from friction (pistons going up & down, &c) and from pumping losses, so obviously it is not more efficient.

The danger/illegality issues have been addressed elsewhere, so I'll just point out that what you believe - coasting is unsafe, big SUVs are safer than small cars, all your kids are above average - may not match reality :-)
I guess the next eco evolution in engines might be a compression release when your engine goes into DFCO...?
__________________

  Reply With Quote
Old 11-04-2012, 08:44 AM   #13 (permalink)
EcoModding Lurker
 
Join Date: Oct 2012
Location: muskoka
Posts: 80

Speedy Gonzales - '11 Ford Fiesta SES
Thanks: 7
Thanked 10 Times in 6 Posts
Quote:
Originally Posted by mcrews View Post
1. topic is addressed in other threads.
2. 'all modern engines??????? 1984 and up? 1999 and up?
3. Majority of posters here have 'older' cars.
4. the issue of engine on/ neutral coasting has been determined to be manufacturer specific. Alos addressed in other threads.

for example, the last year of the ford taurus (mayby older ones also) DOES NOT gain any advantages. the rpms DO NOT drop
My 02 (02-06) Infiniti Q45 DOES benefit from engine on/ nuetral coasting DOES make a difference.
Ok, engines newer than 1965!!
I was obviously referring to my car, as I have no idea what model cars other users are driving or what year they were manufactured or whether or not they employ this technique...
__________________

  Reply With Quote
Old 11-04-2012, 10:03 AM   #14 (permalink)
The PRC.
 
Join Date: Oct 2009
Location: Elsewhere.
Posts: 5,304
Thanks: 285
Thanked 535 Times in 384 Posts
Quote:
Originally Posted by bestclimb View Post
Where are you getting your information for this? If you are using your Ultragauge you have to tell it if you have DFCO it won't tell you.
My MPG goes to 999.
__________________
[I]So long and thanks for all the fish.[/I]
  Reply With Quote
Old 11-04-2012, 11:11 AM   #15 (permalink)
Smeghead
 
Join Date: Oct 2009
Location: South Central AK
Posts: 933

escort - '99 ford escort sport
90 day: 42.38 mpg (US)

scoobaru - '02 Subaru Forester s
90 day: 28.65 mpg (US)
Thanks: 32
Thanked 146 Times in 97 Posts
Quote:
Originally Posted by Arragonis View Post
My MPG goes to 999.
So does mine but I had to tell the Ultra gauge that I had DFCO.
__________________

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

One mile of road will take you one mile, one mile of runway can take you around the world.
  Reply With Quote
Old 11-04-2012, 11:29 AM   #16 (permalink)
Always Too Busy
 
Flakbadger's Avatar
 
Join Date: Apr 2012
Location: Oregon
Posts: 561

White Lightning - '17 Nissan Leaf SV
Team Leaf
90 day: 149.2 mpg (US)
Thanks: 404
Thanked 178 Times in 130 Posts
Quote:
Originally Posted by bestclimb View Post
Where are you getting your information for this? If you are using your Ultragauge you have to tell it if you have DFCO it won't tell you.
Aha, see I didn't know that, I figured it would detect it automatically. Currently, my instantaneous MPG drops quite suddenly when shifting from neutral, to in-gear, even if my RPM's are around 3k.

Quote:
Originally Posted by Arragonis View Post
Does yours have the same rule as mine - i.e. > 1400 rpm ? These results could be due to the fuel required to maintain idle (~900 rpm) out of gear vs what the ECU thinks is needed at whatever rpm in 3rd at 40 MPH is - I would google this last factor but your US Yaris might be different from our UK one.
I will research it; I will say that in my pre-Ultragauge days, I noticed a distinct jump from the engine when slowing in-gear and my RPM's dropped below around 1500. I assumed at that time I was experiencing DFCO, and later assumed my car was not doing it because of the Ultragauge's apparent lack of DFCO recognition.

Hm, learn something new every day, eh?
__________________
Nissan Leaf driver? Join me in Team Leaf and feel smugly superior about our MPGe

Current Car: White Lightning

----------------------------------------------

Retired Car: Betty White

Last edited by Flakbadger; 11-04-2012 at 11:48 AM..
  Reply With Quote
Old 11-04-2012, 12:32 PM   #17 (permalink)
Smeghead
 
Join Date: Oct 2009
Location: South Central AK
Posts: 933

escort - '99 ford escort sport
90 day: 42.38 mpg (US)

scoobaru - '02 Subaru Forester s
90 day: 28.65 mpg (US)
Thanks: 32
Thanked 146 Times in 97 Posts
cool. You may be able to "see" what is going on by adding the O2 voltage gauge to your front page for a bit. Once your car is warmed up it will bounce around a bit as the computer corrects the fueling. When you decelerate you will see it go into open loop (little circle thingie on the top right) and the o2 will go lean (0 volts I think).

A side note that I should probably post in instrumentation as well. If you do little to no EOC or P&G where the car's computer is going back and forth from open and closed loop what follows really does not matter. If you are operating in open loop more frequently (such as after restart from EOC or P&G) you may get some odd readings.

I tinkered with Injector Cutoff (what Ultra Gauge calls DFCO) for a while and verified what I was seeing on the ultra gauge with my mpguino just tapped into the injector signal. Ultra Gauge can not "see" what the injectors are doing. It can see open loop and throttle position. So by knowing that your foot is off the throttle and the engine is in open loop it knows you are in Injector Cutoff but only after it has gone into close loop once. If you pulse and glide or EOC on the restart the computer is in open loop mode but Ultra Gauge did not power cycle. UG still thinks the car is being driven "normaly" it sees open loop, with little to no throttle position and "thinks" Injector Cutoff. End result is after an EOC to a stop sign, bump start, get going again shift to 5th and light load cruse to the next coast the UG though I was in Injector Cutoff the whole time (other than the acceleration)

The directions say

Quote:
Injector cutoff is disabled when set to zero, and is disabled by default. To enable Injector cutoff detection, set the value equal
to seven times the engine size in liters, rounded up to a whole number. For example, for a 2.3L engine the value should be set
to 2.3x7= 16.1  17. The value is not crucial and this calculation represents a best estimate.
When enabled and injector cutoff occurs, the Instantaneous MPG will read 999.9, and the Instantaneous Gallons/hour will read
0.0
I would suggest if you are seeing this effect, set the value as low as possible with the Ultra Gauge still seeing Injector Cutoff when you lift off. By the directions I should set the value to 14 (2l engine x7) Mine is set to around 4 or 5 now. Ultra Gauge is only falsely detecting Injector Cutoff after EOC restart and idle or very low power settings right after restart. Once the car goes back into closed loop mode all is well.
__________________

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

One mile of road will take you one mile, one mile of runway can take you around the world.
  Reply With Quote
The Following User Says Thank You to bestclimb For This Useful Post:
Flakbadger (11-04-2012)
Old 11-05-2012, 08:22 AM   #18 (permalink)
The PRC.
 
Join Date: Oct 2009
Location: Elsewhere.
Posts: 5,304
Thanks: 285
Thanked 535 Times in 384 Posts
Quote:
Originally Posted by bestclimb View Post
So does mine but I had to tell the Ultra gauge that I had DFCO.
My old-school SG2 just shows the MPG jump. I don't think you have to tell it about DFCO but its been a while since I read the manual.

Pondering asking for an Ultragauge for Christmas - I have been good all year
__________________
[I]So long and thanks for all the fish.[/I]
  Reply With Quote
The Following User Says Thank You to Arragonis For This Useful Post:
wungun (11-05-2012)
Old 11-07-2012, 05:01 AM   #19 (permalink)
Master EcoModder
 
euromodder's Avatar
 
Join Date: Jul 2010
Location: Belgium
Posts: 4,667

GasDwarf - '13 Volkswagen up! EcoFuel CNG
Thanks: 176
Thanked 643 Times in 510 Posts
Quote:
Originally Posted by Flakbadger View Post
Conclusion: The Toyota Yaris manual transmission DOES NOT DFCO.
I'd be extremely surprised if it didn't have DFCO - every Toyota I've driven in the last 20 years had it.
  Reply With Quote
Old 11-07-2012, 05:07 AM   #20 (permalink)
Master EcoModder
 
euromodder's Avatar
 
Join Date: Jul 2010
Location: Belgium
Posts: 4,667

GasDwarf - '13 Volkswagen up! EcoFuel CNG
Thanks: 176
Thanked 643 Times in 510 Posts
Quote:
Originally Posted by Flakbadger View Post
I will say that in my pre-Ultragauge days, I noticed a distinct jump from the engine when slowing in-gear and my RPM's dropped below around 1500.
Sounds like the idle fuel regulator is kicking in to keep the engine running after using DFCO - though around 1500 seems a bit high for it to kick in.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com