Go Back   EcoModder Forum > EcoModding > Hypermiling / EcoDriver's Ed
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-18-2013, 03:41 AM   #1 (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 145 Times in 97 Posts
throttle tap to initiate DFCO

Noted something a while a go and have been looking for it lately. When engine braking (with a down shift) I have noted that my Subaru does not always enter DFCO, even at higher RPM. However, when lifting off even at lowish RPM it always enters DCFO.

When coming down hill and down shifting if I don't feel computer has cut fuel or note that it is still in closed loop I can blip the throttle and it will go open loop and zero fuel consumption immediately. The "blip" is not even enough to feel, just enough for the computer to see a change in throttle position.

I will have to check for this in the escort.

__________________

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
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-22-2013, 06:09 PM   #2 (permalink)
Master EcoModder
 
jedi_sol's Avatar
 
Join Date: Mar 2009
Location: Tustin, CA
Posts: 929

2013 STi *SOLD* - '13 Subaru Impreza WRX STi
Subaru
Sports Cars
Team Turbocharged!
90 day: 26.59 mpg (US)

1996 Geo Metro *RETIRED from Ecomodding* - '96 Geo Metro Base
90 day: 58.68 mpg (US)
Thanks: 368
Thanked 378 Times in 236 Posts
in for results...i just got a 2013 subaru sti...i dont have a scangauge yet so i can't tell if mine goes into dfco either.
__________________







See the rest of the Sti project log:
http://ecomodder.com/forum/showthrea...log-26612.html
  Reply With Quote
Old 07-22-2013, 07:31 PM   #3 (permalink)
Pishtaco
 
SentraSE-R's Avatar
 
Join Date: Jun 2009
Location: Bay Area, California
Posts: 1,485

Mean Green Toaster Machine - '06 Scion xB
Team Toyota
90 day: 48.92 mpg (US)
Thanks: 56
Thanked 285 Times in 181 Posts
DFCO parameters vary with the car. My '02 Nissan Sentra SE-R didn't enter DFCO unless it was in gear, engine rpms >2500, and relative TPS was at idle position (11?). That meant I had to be going faster than 65 mph in 6th gear for DFCO to kick in.

My '06 Scion xB, OTOH, is a DFCOing pleasure. It enters DFCO when in gear, engine rpms >1500, and relative TPS at idle (11). That means it goes into DFCO at any speed >35 mph in 5th gear.

FWIW, I've never had to blip the throttle of either of those cars (both manual trannys) to enter DFCO
__________________
Darrell

Boycotting Exxon since 1989, BP since 2010
Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac? George Carlin
Mean Green Toaster Machine
49.5 mpg avg over 53,000 miles. 176% of '08 EPA
Best flat drive 94.5 mpg for 10.1 mi
Longest tank 1033 km (642 mi) on 10.56 gal = 60.8 mpg
  Reply With Quote
Old 07-22-2013, 11:08 PM   #4 (permalink)
EcoModding Lurker
 
Join Date: Apr 2011
Location: Muskegon,MI
Posts: 35

The Beast - '93 Fleetwood Flair includes kitchen sink
90 day: 9.2 mpg (US)
Thanks: 0
Thanked 7 Times in 6 Posts
Quote:
Originally Posted by bestclimb View Post
Noted something a while a go and have been looking for it lately. When engine braking (with a down shift) I have noted that my Subaru does not always enter DFCO, even at higher RPM. However, when lifting off even at lowish RPM it always enters DCFO.

When coming down hill and down shifting if I don't feel computer has cut fuel or note that it is still in closed loop I can blip the throttle and it will go open loop and zero fuel consumption immediately. The "blip" is not even enough to feel, just enough for the computer to see a change in throttle position.

I will have to check for this in the escort.
IF DFCO means that the ECO cuts the fuel on decelerate, then I got it. My "The Beast" RV will cut the fuel mostly anything over 50 mph. The MPGuino shows 999 mpg. Lower than that it shows 60-30 mpg as it slows down. 454 Chevy w/ 4 speed automatic tranny.
I LOVE to coast! 16 mpg, best so far.
  Reply With Quote
Old 07-22-2013, 11:39 PM   #5 (permalink)
Master EcoModder
 
cbaber's Avatar
 
Join Date: Feb 2012
Location: Missouri
Posts: 540

Lean and Mean - '98 Honda Civic HX
Team Honda
90 day: 46.69 mpg (US)
Thanks: 30
Thanked 190 Times in 110 Posts
Sometimes when I am engine braking the fuel will not shut off. If I apply a little throttle and resume engine braking, the fuel shuts off. I am not sure if this is is actually happening or if the Scangauge is just having a little glitch.

I wouldn't sweat it to much. If you are engine braking you have no load (negative load?) on the engine and the cars computer is not going to deliver hardly any fuel if it isn't cut off.
__________________
1998 Honda Civic HX - My Project Thread

  Reply With Quote
Old 07-23-2013, 12:47 AM   #6 (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 145 Times in 97 Posts
Quote:
Originally Posted by cbaber View Post
Sometimes when I am engine braking the fuel will not shut off. If I apply a little throttle and resume engine braking, the fuel shuts off. I am not sure if this is is actually happening or if the Scangauge is just having a little glitch.

I wouldn't sweat it to much. If you are engine braking you have no load (negative load?) on the engine and the cars computer is not going to deliver hardly any fuel if it isn't cut off.
What you describe is exactly the behavior the forester does. Ultra Gauge shows closed loop and 60-80mpg, slight tap on the throttle and then Ultra Gauge shows open loop along with 9999999. I can also feel a slight increase in deceleration.

Not much fuel but enough to harsh my grove. On sections where the computer does not shut off fueling I get 60-80 mpg, if I were to just coast at idle I would be getting 170+-50. Granted not not a large % of a hill but a bit of savings if aware of the behavior for no increase in travel time.
__________________

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 08-05-2013, 03:04 PM   #7 (permalink)
Master EcoModder
 
jedi_sol's Avatar
 
Join Date: Mar 2009
Location: Tustin, CA
Posts: 929

2013 STi *SOLD* - '13 Subaru Impreza WRX STi
Subaru
Sports Cars
Team Turbocharged!
90 day: 26.59 mpg (US)

1996 Geo Metro *RETIRED from Ecomodding* - '96 Geo Metro Base
90 day: 58.68 mpg (US)
Thanks: 368
Thanked 378 Times in 236 Posts
I got my torque app installed. It seems on my 2013 Sti, dfco happens in any gear at any speed...as long as the rpms are above 1K rpm.

It seems this car is very liberal with dfco.
__________________







See the rest of the Sti project log:
http://ecomodder.com/forum/showthrea...log-26612.html
  Reply With Quote
Old 08-05-2013, 03:23 PM   #8 (permalink)
Master EcoModder
 
Join Date: Jan 2011
Location: Iowa
Posts: 1,130

Impala FFV - '10 Chevy Impala LT
90 day: 29.54 mpg (US)

XFE Coupe - '09 Chevy Cobalt XFE
Team Chevy
90 day: 37.44 mpg (US)

Penny's Rogue - '15 Nissan Rogue SL AWD
90 day: 29 mpg (US)

Cam's Rogue - '11 Nissan Rogue SV AWD
90 day: 26 mpg (US)

Elantra - '17 Hyundia Elantra SE
Team Hyundai
90 day: 44.68 mpg (US)

Cruze Limited - '16 Chevy Cruze Limited LT
90 day: 30 mpg (US)
Thanks: 268
Thanked 216 Times in 183 Posts
With the cobalt I have to be at 2,000 rpm for DFCO to kick in (55 mph in 5th). I'll try the throttle blip at lower speeds on the way home. SGII mpg or gph doesn't pick it up, but goes open loop and factory gauge 99. Goes back to closed loop at about 1400 rpm and 40 mph.

Edit: tried on the way home, no difference tapping the throttle with the cobalt.


Last edited by roosterk0031; 08-05-2013 at 10:05 PM..
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com