Go Back   EcoModder Forum > EcoModding > Success Stories
Register Now
 Register Now

Now available from EcoModder: ScanGauge II fuel economy gauge.  Click for details.  

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-14-2012, 11:05 PM   #1 (permalink)
EcoModding Apprentice
 
ever_green's Avatar
 
Join Date: May 2011
Location: Toronto
Posts: 219

Suby - '09 Subaru Impreza 2.5i
90 day: 38.64 mpg (US)
Thanks: 8
Thanked 57 Times in 21 Posts
+4mpg now just by advancing IGN

i have been monitoring ignition timing on my impreza and cruising on the highway i recorded between 32-34 degrees IGN. i have heard modern knock sensors in new cars are pretty advanced and sometimes you don't actually even need an ecu tune to advance/retard timing. So I decided to run 91 octane and see if the car will 'advance' the ignition automatically and voila. My ignition timing according to scangauge now is 45 deg at highway speeds. i do have a before and after video.

this before video is from a while back but you can kind of make out the 35 ignition timing and ~33mpg


this one is from today and you can make out a whopping 45 deg IGN and ~37mpg on same stretch of road at same speed:


the thing that amazed me was how quickly the car adjusted the ignition timing and how much difference timing advance made. just after a few minutes cruising on the highway the ignition timing went as far as it could without knocking for ~4 more MPG. i remember playing with A/F by leaning out the ECU map, but that made not much difference and it made my engine run at unsafe temperatures. So this is much better. however i don't do any highway driving so it's good old 87 octane for me. but it is obvious to me now that my car CAN take advantage of higher anti-knocking index gas. the only downside is extra cost of 91 octane and increased engine braking. anyone else experienced this?

  Reply With Quote
The Following User Says Thank You to ever_green For This Useful Post:
radioranger (12-15-2012)
Old 12-15-2012, 02:01 AM   #2 (permalink)
Master EcoModder
 
mcrews's Avatar
 
Join Date: Oct 2009
Location: Texas
Posts: 3,047

The Q Sold - '02 Infiniti Q45 Sport
90 day: 23.08 mpg (US)

Kia - '06 Kia Sportage EX
90 day: 23.63 mpg (US)
Thanks: 1,222
Thanked 491 Times in 371 Posts
my infiniti 2002 Q45 got lower mpg on lower octane, and the timing dropped to 29 at cruise.
__________________
MetroMPG: "Get the MPG gauge - it turns driving into a fuel & money saving game."

ECO MODS PERFORMED:
First: ScangaugeII
http://ecomodder.com/forum/showthrea...eii-23306.html

Second: Grille Block
http://ecomodder.com/forum/showthrea...e-10912-2.html

Third: Full underbelly pan
http://ecomodder.com/forum/showthrea...q45-11402.html

Fourth: rear skirts and 30.4mpg on trip!
http://ecomodder.com/forum/showthrea...tml#post247938
  Reply With Quote
Old 12-15-2012, 07:06 AM   #3 (permalink)
radioranger
 
Join Date: Dec 2011
Location: Canton CT
Posts: 442
Thanks: 140
Thanked 37 Times in 30 Posts
Great info, My Ranger has a distributor , the last year for them was 88 , anyway the ignition modules that plug in can go bad and one of the symptoms is a loss of advance, one day i started the truck and all it would do was idle, even grabbing the throttle linkage wouldnt rev it up just stall, so something for the late 80's early 90's Ford guys to think about, they make aftermarket modules with different specs, but havent tried any ,
  Reply With Quote
Old 12-15-2012, 07:20 PM   #4 (permalink)
#1 e85 phev hybrid owner!
 
Join Date: May 2012
Location: Central, VA
Posts: 2,508

Honda - '10 Honda Insight ex

Kick - '95 Suzuki Sidekick ljx
Thanks: 1,403
Thanked 242 Times in 203 Posts
Might want to try some BP gas. The newer insight runs at almost 11 to 1 compression with its dual spark plug iDsi ignition. Myself and a few owners notice with BP or mid grade gas it will pull more timing and not vary the rpm or cvt ratio that often under a light load vs regular or the cheap stuff. Ive been buying my gas at sheetz as its 3 cents off with a membership card, but I like the behavior better on BP fuel.
  Reply With Quote
Old 12-16-2012, 02:17 AM   #5 (permalink)
Master EcoModder
 
mechman600's Avatar
 
Join Date: Jul 2008
Location: Surrey, BC
Posts: 1,211

The Matrix - '07 Toyota Matrix XR Auto
90 day: 27.52 mpg (US)

Wee - '06 Suzuki DL650 VStrom
90 day: 50.35 mpg (US)

Si - '98 Honda Civic Si
90 day: 37.88 mpg (US)
Thanks: 186
Thanked 254 Times in 158 Posts
I would say that the 4 mpg difference is because of the lower ethanol content in the 91 octane gas, not the advanced ignition timing.

Your engine is smart enough to advance the timing when it sees high octane gas because higher octane gas has a slower flame front and requires more advance for the same power output.
  Reply With Quote
Old 12-16-2012, 06:33 PM   #6 (permalink)
Master Ecomadman
 
arcosine's Avatar
 
Join Date: Nov 2010
Location: Chicago area
Posts: 895

sc1 - '98 saturn sc1
Team Saturn
90 day: 43.17 mpg (US)

Airplane Bike - '11 home built Carp line Tour

C - '97 Vision R40

tractor - '66 International Cub cadet 129

Y2K - '00 honda Insight

minivan - '93 oldsmobile Silouette
Thanks: 11
Thanked 159 Times in 115 Posts
My saturn gets much better mpg with premium. With regular the timing retards to -5 degrees when hot at low rpm full throttle.
__________________
- Tony

  Reply With Quote
The Following User Says Thank You to arcosine For This Useful Post:
Cobb (12-16-2012)
Old 12-16-2012, 09:00 PM   #7 (permalink)
#1 e85 phev hybrid owner!
 
Join Date: May 2012
Location: Central, VA
Posts: 2,508

Honda - '10 Honda Insight ex

Kick - '95 Suzuki Sidekick ljx
Thanks: 1,403
Thanked 242 Times in 203 Posts
Ive notice with the grill block when the temp gets above 185 the i2 starts to retard timing and upping the cvt ratio.
  Reply With Quote
Old 12-19-2012, 10:02 PM   #8 (permalink)
halos.com
 
Join Date: Oct 2009
Location: Cibolo, TX
Posts: 471

ECONORAM - '07 Dodge RAM 1500 QC SLT flex-fuel
90 day: 18.76 mpg (US)

the Avenger - '08 Dodge Avenger SXT
90 day: 27.06 mpg (US)
Thanks: 308
Thanked 70 Times in 61 Posts
Send a message via Yahoo to ECONORAM
When I had my 84 and 90 Jettas, each with a 1.8L, I saw a similar FE increase. The 84 I was able to set the timing up a few degrees at the distributor--no knock sensor. The 90 did have a knock sensor, and from the factory it had only 4*BTDC at idle. With 91 octane, I was able to bump it to 8* and I recall getting about 2 mpg.
__________________
  Reply With Quote
Old 12-19-2012, 11:31 PM   #9 (permalink)
EcoModding Apprentice
 
ever_green's Avatar
 
Join Date: May 2011
Location: Toronto
Posts: 219

Suby - '09 Subaru Impreza 2.5i
90 day: 38.64 mpg (US)
Thanks: 8
Thanked 57 Times in 21 Posts
Quote:
Originally Posted by Cobb View Post
Ive notice with the grill block when the temp gets above 185 the i2 starts to retard timing and upping the cvt ratio.
that's strange on days that i use grille block my timings usually advance furthest and overall MPG improves. sometimes if i don't use a grille block my timing would not hit 44-46 deg the whole day...not sure why.

Quote:
Originally Posted by mechman600 View Post
I would say that the 4 mpg difference is because of the lower ethanol content in the 91 octane gas, not the advanced ignition timing.
87 octane and 91 octane petro canada gas are both 10% ethanol. only shell v-power 91 here is 0% ethanol. i used 91 petro canada.
  Reply With Quote
Old 12-19-2012, 11:36 PM   #10 (permalink)
Master EcoModder
 
RobertISaar's Avatar
 
Join Date: Jul 2012
Location: camden, MI
Posts: 294

MC SBX - '95 Chevrolet Monte Carlo LS
Last 3: 29.75 mpg (US)
Thanks: 4
Thanked 39 Times in 32 Posts
Quote:
Originally Posted by ever_green View Post
that's strange on days that i use grille block my timings usually advance furthest and overall MPG improves. sometimes if i don't use a grille block my timing would not hit 44-46 deg the whole day...not sure why.
because you've changed the conditions.

with a grille block in place, the engine is under less load since there is less aerodynamic drag to fight against. an engine at the same RPM, but with lower load can GENERALLY get away with running more advance without running into knock.

__________________
  Reply With Quote
Reply  Post New Thread

Thread Tools





Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com