worse mpg with 93 octane - Ranger-Forums - The Ultimate Ford Ranger Resource


4.0L OHV & SOHC V6 Tech General discussion of 4.0L OHV and SOHC V6 Ford Ranger engines.

Reply
 
LinkBack Thread Tools Search this Thread
  #1  
Old 01-19-2009
CapeFear562's Avatar
Member
Thread Starter
 
Join Date: Mar 2007
Location: Broadway, NC
Posts: 50
worse mpg with 93 octane

Has anyone else had the problem with getting worse mpg running 93 octane then on 87 octane. I tried the search function, but nothing came up.
Reply With Quote
  #2  
Old 01-19-2009
Blackonblackfx4's Avatar
Member
iTrader: (1)
 
Join Date: Jan 2009
Location: Edmonton, Alberta
Posts: 914
Yeah i tried it once, i think i was using more fuel with Shell V power. Im gunna pull on my truck to the airport one of these days and fill it up with Av. Gas. its 100 octane.
Reply With Quote
  #3  
Old 01-19-2009
Toreador4x4's Avatar
Member
iTrader: (6)
 
Join Date: Apr 2007
Location: Livonia, MI
Posts: 3,958
i did

on my ranger i get 19-20 on 87 octane and 16-17 on 94 octane

on my motorcycle i get 51 on 89 octane and 40 on 94 octane
Reply With Quote
  #4  
Old 01-19-2009
CapeFear562's Avatar
Member
Thread Starter
 
Join Date: Mar 2007
Location: Broadway, NC
Posts: 50
i have to admit though...i runs great...i can definitely tell a difference between 93 and 89 octane. I just didn't think my fuel mileage would go down
Reply With Quote
  #5  
Old 01-19-2009
Igobytwitch's Avatar
Member
 
Join Date: Oct 2008
Location: Cocoa Beach, Florida
Posts: 504
Your computer isn't tuned for it
Reply With Quote
  #6  
Old 01-19-2009
HAZZARDJOHN's Avatar
Member
 
Join Date: Dec 2005
Location: Wyoming MN
Posts: 2,400
Without a tune, you are wasting your money, polluting more and clogging you Cat. If you can tell a difference you are feeling what you want to feel.

http://www.ftc.gov/bcp/edu/pubs/cons...tos/aut12.shtm

~HJ
Reply With Quote
  #7  
Old 01-19-2009
whippersnapper02's Avatar
RF Veteran
iTrader: (1)
 
Join Date: Sep 2006
Location: Earth, Milky Way Galaxy
Posts: 7,415
If the truck doesn't need it then don't run it. There was an article in Sport Compact Car like 5 years ago and they dynoed a Honda Accord V6 with the recommended 87 then dynoed it with 91. The engine made 10hp less with the higher octane fuel.
Reply With Quote
  #8  
Old 01-19-2009
FireRanger's Avatar  
Join Date: May 2004
Location: CT
Posts: 0
What you are feeling is all in your head. It is actually degrading performance. It is degrading your MPG. And if you keep using it, it is going to degrade the rest of your engine with carbon and screw up your entire emissions system.

You computer must be reprogrammed to properly use any octane other than 87.
Reply With Quote
  #9  
Old 01-19-2009
Fx4BlackRanger's Avatar
Member
 
Join Date: Feb 2008
Location: Malibu, California
Posts: 495
Damit i wish i had known this, i have not done it every single fill up but on multiple occasions i have, on a new truck do you think its done any damedge yet? i have about 5700 miles on it and ive maybe put 93 in...7 times?
getting about 270 miles per tank
Reply With Quote
  #10  
Old 01-19-2009
HAZZARDJOHN's Avatar
Member
 
Join Date: Dec 2005
Location: Wyoming MN
Posts: 2,400
Quote:
Originally Posted by Fx4BlackRanger View Post
Damit i wish i had known this, i have not done it every single fill up but on multiple occasions i have, on a new truck do you think its done any damedge yet? i have about 5700 miles on it and ive maybe put 93 in...7 times?
getting about 270 miles per tank
I doubt it, Just hitting your wallet.
Reply With Quote
  #11  
Old 01-19-2009
CapeFear562's Avatar
Member
Thread Starter
 
Join Date: Mar 2007
Location: Broadway, NC
Posts: 50
I appreciate the info and the article...didn't realize 93 would have that kind of affect...im still pretty sure that it has helped the low end torque just from the way i pull trailers there is a difference...granted it does seem to fall off a little after 2000 rpm compared to normal
Reply With Quote
  #12  
Old 01-19-2009
whippersnapper02's Avatar
RF Veteran
iTrader: (1)
 
Join Date: Sep 2006
Location: Earth, Milky Way Galaxy
Posts: 7,415
Butt dyno is usually wrong unless its a major increase in power.
Reply With Quote
  #13  
Old 01-19-2009
JRacer's Avatar
Member
iTrader: (2)
 
Join Date: May 2008
Location: Watson, Louisiana
Posts: 1,085
umm. what's stated above isnt exactly true. For a while i was using Shell 87 octane fuel. I noticed a rough idle and the tach was sitting well below 1000. Filled er up with Shell V-Power 93 octane and the truck idled higher and smoother.
Reply With Quote
  #14  
Old 01-19-2009
FireRanger's Avatar  
Join Date: May 2004
Location: CT
Posts: 0
Quote:
Originally Posted by JRacer View Post
umm. what's stated above isnt exactly true. For a while i was using Shell 87 octane fuel. I noticed a rough idle and the tach was sitting well below 1000. Filled er up with Shell V-Power 93 octane and the truck idled higher and smoother.
Which means there is something wrong with your engine. You should fix it rather than continuing to make it worse and throwing money in it.
Reply With Quote
  #15  
Old 01-19-2009
davidw's Avatar
Member
 
Join Date: Aug 2008
Location: Bow,WA
Posts: 207
i have a superchip, said it needed 92 octane or higher to work right. my truck burns the higher octane fuels to quick, so i actually got better mpg with 87 or 89 octane (regular) then any other grade
Reply With Quote
  #16  
Old 01-19-2009
whippersnapper02's Avatar
RF Veteran
iTrader: (1)
 
Join Date: Sep 2006
Location: Earth, Milky Way Galaxy
Posts: 7,415
Quote:
Originally Posted by JRacer View Post
umm. what's stated above isnt exactly true. For a while i was using Shell 87 octane fuel. I noticed a rough idle and the tach was sitting well below 1000. Filled er up with Shell V-Power 93 octane and the truck idled higher and smoother.
Look in your manual. It will say 87. Rangers don't have high compression engines or boost. You don't need the extra octane.
Reply With Quote
  #17  
Old 01-19-2009
rangerdanger01's Avatar
Member
 
Join Date: Sep 2008
Location: New Lenox, IL
Posts: 62
your truck isn't designed to run 93 octane. its not high compression like a corvette where it needs slower burning fuel. 93 is a little bit thicker so it burns slightly slower than 87. when you have high compression you have more horse power but high compression makes the fuel burn faster. semis run completely off of compression which is why diesel fuel is so thick and thats why semis don't have sparkplugs. your engine assuming it is the stock motor is designed to burn most efficiently on 87 octane and anyting else your basically wasting money.
Reply With Quote
  #18  
Old 01-19-2009
FireRanger's Avatar  
Join Date: May 2004
Location: CT
Posts: 0
It isn't really thickness. Its chemical composition.
Reply With Quote
  #19  
Old 01-19-2009
Blackonblackfx4's Avatar
Member
iTrader: (1)
 
Join Date: Jan 2009
Location: Edmonton, Alberta
Posts: 914
Sometimes my 4L SOHC runs rough on regular fuel too misisng every so offten, and my 02 ranger did it as well. Also If I fill up at the cheaper stations it stalls, Shell and Petro Can seam to run smoother though.
Reply With Quote
  #20  
Old 01-20-2009
CBFranger's Avatar
Member
 
Join Date: May 2008
Location: Tampa Bay Area
Posts: 1,029
Quote:
Originally Posted by Igobytwitch View Post
Your computer isn't tuned for it
and....


drumroll please.......


Higher Octane = Lower Energy per volume unit.
Reply With Quote
  #21  
Old 01-20-2009
CBFranger's Avatar
Member
 
Join Date: May 2008
Location: Tampa Bay Area
Posts: 1,029
Quote:
Originally Posted by rangerdanger01 View Post
your truck isn't designed to run 93 octane. its not high compression like a corvette where it needs slower burning fuel. 93 is a little bit thicker so it burns slightly slower than 87. when you have high compression you have more horse power but high compression makes the fuel burn faster. semis run completely off of compression which is why diesel fuel is so thick and thats why semis don't have sparkplugs. your engine assuming it is the stock motor is designed to burn most efficiently on 87 octane and anyting else your basically wasting money.
Higher octane is not slower burning, it has a higher temperature of ignition.

Quote:
Originally Posted by fddriver02 View Post
Look in your manual. It will say 87. Rangers don't have high compression engines or boost. You don't need the extra octane.
No, but higher octane can advance the timing. The closer to TDC you spark it, the more energy out of it you are going to get. Hence why running E-85 doesnt give a 30% drop in mileage when E-85 has 30% less energy than 87 oct gas. Ethanol has an "octane" rating of 110 IIRC.
Reply With Quote
  #22  
Old 01-20-2009
IN2 FX4's Avatar
Member
 
Join Date: Feb 2005
Location: Costa Mesa, CA
Posts: 855
There is so much misinformation in this post and I hope nobody reads it and believes all of it.

I have never read anywhere that high octane fuel has a temperature of ignition. It does tend to burn slower and more uniformly. It also resists pre-ignition. High octane fuel cannot change timing but advancing the timing is done when using higher octane if the engine does not have higher compression to utilize the higher octane fuel. Advancing the timing is not closer to TDC, it is farther away from TDC.

High octane fuel is not thicker. I use 110 to 112 octane in my race car at 14:1 compression and that fuel is no thicker than 87 octane pump gas.

Be careful about using 100 octane Av-gas. It is my understanding that even though it is called unleaded, it still has a very small amount of lead in it which can damage your catalytic converter. I don't know this for fact but I would recommend investigating this a little before trying it.

The slight miss you get at idle with 87 may just be a lean miss. They run the engine lean to reduce emissions. A slightly rich mixture will will run smoother. Using higher octane will have a tendency to run slightly rich because you don't get a complete burn due to the slower burn. This is hypothetical and may not be fact. Just a suggestion based on a few facts.
Reply With Quote
  #23  
Old 01-20-2009
FireRanger's Avatar  
Join Date: May 2004
Location: CT
Posts: 0
Aviation fuel is not called unleaded at all. It is called 100LL which stands for 100 Octane low lead. It is in fact leaded gasoline and shouldn't be used in autos designed for unleaded fuel.

Gary, this octane thing comes up a few times a year and i must say it is funny to read all the various misconceptions. I blame the fuel companies advertising. They always call it premium or super or whatever. When in reality, there is nothing premium or super about it other than the cost.
Reply With Quote
  #24  
Old 01-20-2009
CBFranger's Avatar
Member
 
Join Date: May 2008
Location: Tampa Bay Area
Posts: 1,029
Quote:
Originally Posted by IN2 FX4 View Post
There is so much misinformation in this post and I hope nobody reads it and believes all of it.

I have never read anywhere that high octane fuel has a temperature of ignition. It does tend to burn slower and more uniformly. It also resists pre-ignition. High octane fuel cannot change timing but advancing the timing is done when using higher octane if the engine does not have higher compression to utilize the higher octane fuel. Advancing the timing is not closer to TDC, it is farther away from TDC.


Incase you missed automechanics 101, advancing the timing is moving it closer towards TDC. The spark plug fires before the piston reaches TDC.

Knocking happens because of two reasons, hot spots, and charge temperature. Longer carbon chains have a higher temperature of combustion. In theory, longer carbon chains also have more energy, but the way they blend it, there is actually less energy.

Thus, a higher octane will allow you to advance timing which results in a quicker, more complete combustion.

So if you are so dumb as to think that I was saying changing the fuel changes its timing as if spark timing were magic....well god save your soul and perhaps a reading comprehension class and giving people the benefit of the doubt would would benefit you in life.

Last edited by CBFranger; 01-20-2009 at 01:19 PM.
Reply With Quote
  #25  
Old 01-20-2009
CBFranger's Avatar
Member
 
Join Date: May 2008
Location: Tampa Bay Area
Posts: 1,029
BTW, longer carbon chains also tend to be more viscous and higher in density...so you're wrong there as well. Whether it is actually true in real world application, I doubt.
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Timing & Octane vs MPG wydopnthrtl General Ford Ranger Discussion 11 11-01-2008 02:17 PM
MPG's are getting worse 00xlt4x4 4.0L OHV & SOHC V6 Tech 6 11-11-2007 08:09 AM
98 3.0 MPG Log (shows how mods affected MPG) Marcaronio 2.9L & 3.0L V6 Tech 23 05-11-2007 09:11 PM
Squealing/Chirping Noise getting worse and worse... pastfinder 2.9L & 3.0L V6 Tech 25 05-06-2007 10:58 AM
why would my new alpine speakers sound worse than my stock speakers? james13f Audio & Video Tech 21 04-03-2005 06:01 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -6. The time now is 07:32 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.