Search



Go Back   MustangForums.com > Ford Mustang Tech > 2005 - 2014 Mustangs
Sign in using an external account
Register Forgot Password?
Search

2005 - 2014 Mustangs Discussions on the latest S197 model Mustangs from Ford.
Sponsored by Latemodel Restoration


Welcome to Mustang Forums!
Welcome to Mustang Forums.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!


Reply
 
 
 
 
Thread Tools Search this Thread
Old 07-04-2013, 02:40 PM   #1
dared3vil0
1st Gear Member
 
Join Date: Jan 2012
Vehicle: SOON 00-04 GT Manual
Location: BC
Posts: 72
Default 87 Octane question...

Hello all, i'd like to start off by saying a couple things... 1) Yes i searched and all i could find are results related to tuning for a different octane, or GT octane questions. 2) My question is related to a STOCK 14' 3.7.

I didn't see a "premium fuel is recommended/required sticker anywhere, but i have seen a couple people talking on various Mustang forums that the 3.7 isn't really tuned for 87, that it WILL run on it without too much knock, but power and fuel economy suffer greatly. Anyone know if this is true? Is it worth going to 91? Thanks everyone!
This ad is not displayed to registered or logged-in members.
Register your free account today and become a member on Mustang Forums!
dared3vil0 is offline   Reply With Quote
Old 07-04-2013, 03:56 PM   #2
AzPete
4th Gear Member
 
AzPete's Avatar
 
Join Date: Aug 2008
Vehicle: 08 GT Vert, 02 GT Vert
Location: Panama City, FL
Posts: 1,061
Default

What is recommended in the manual?
__________________
AzPete
Retired USAF
Panama City, Fl.
I wake up in the morning with nothing to do and by supper time, I have half of it done.

2008 GT Vert, stock
2000 Lightning, s/c, tuned, Basanni, built tranny
Previous Mustangs:4 - '66 Coupes(silver/blue/grey/red) '87 GT HO, '00/'02/'07 GT Vert(red)(grey)(black), '68 Coupe, '11 GT/CS
AzPete is offline   Reply With Quote
Old 07-04-2013, 04:05 PM   #3
dared3vil0
1st Gear Member
 
Join Date: Jan 2012
Vehicle: SOON 00-04 GT Manual
Location: BC
Posts: 72
Default

^ It recommends 87, but that wasn't my question. My question was related to power and fuel economy on premium...
dared3vil0 is offline   Reply With Quote
Old 07-04-2013, 05:29 PM   #4
AzPete
4th Gear Member
 
AzPete's Avatar
 
Join Date: Aug 2008
Vehicle: 08 GT Vert, 02 GT Vert
Location: Panama City, FL
Posts: 1,061
Default

I realize what you asked....wasting your money with premium unless your car can adapt like the 5.0 in the GT.
__________________
AzPete
Retired USAF
Panama City, Fl.
I wake up in the morning with nothing to do and by supper time, I have half of it done.

2008 GT Vert, stock
2000 Lightning, s/c, tuned, Basanni, built tranny
Previous Mustangs:4 - '66 Coupes(silver/blue/grey/red) '87 GT HO, '00/'02/'07 GT Vert(red)(grey)(black), '68 Coupe, '11 GT/CS
AzPete is offline   Reply With Quote
Old 07-04-2013, 05:40 PM   #5
dared3vil0
1st Gear Member
 
Join Date: Jan 2012
Vehicle: SOON 00-04 GT Manual
Location: BC
Posts: 72
Default

Quote:
Originally Posted by AzPete View Post
I realize what you asked....wasting your money with premium unless your car can adapt like the 5.0 in the GT.
Considering i've owned it for 3 days and haven't needed to fill up yet, i'd wager a bet i haven't wasted a cent. Thanks for playing.
dared3vil0 is offline   Reply With Quote
Old 07-04-2013, 06:29 PM   #6
Lem-06
4th Gear Member

 
Lem-06's Avatar
 
Join Date: Sep 2011
Posts: 1,172
Default

Unless the control unit can adapt to higher octane then buying a higher octane fuel won't do anything.

The 5.0 can adapt up to 93 iirc to up the power a bit
__________________

SMR#2064
Mods: Steeda CAI, FRPP hotrod's, Black GT500 staggered 18's, GT/CS front end, Airlift Suspension, and more
Lem-06 is offline   Reply With Quote
Old 07-04-2013, 06:40 PM   #7
Weather Man
1st Gear Member

 
Weather Man's Avatar
 
Join Date: Feb 2012
Vehicle: 2008 Ford Mustang GT
Location: MN
Posts: 88
Default

Quote:
Originally Posted by dared3vil0 View Post
My question is related to a STOCK 14' 3.7.

I didn't see a "premium fuel is recommended/required sticker anywhere.

Because there isn't one.

, but i have seen a couple people talking on various Mustang forums that the 3.7 isn't really tuned for 87, that it WILL run on it without too much knock, but power and fuel economy suffer greatly.

They are idiots.

Anyone know if this is true?

No.

Is it worth going to 91?
No, read your owners manual.
__________________
2008 Mustang GT

Weather Man is offline   Reply With Quote
Old 07-04-2013, 06:58 PM   #8
Nuke
6th Gear Member

 
Nuke's Avatar
 
Join Date: Jun 2007
Vehicle: 2007 GT
Location: PA to KY ('07) to IL ('09) to MS ('10) to FL ('11)
Posts: 15,724
Send a message via AIM to Nuke Send a message via Yahoo to Nuke Send a message via Skype™ to Nuke
Default

As AzPete mentioned, you'll waste your money on higher octane if you're not tuned for it. By virtue of the OM not stating anything about using higher octane (like the OM for the 5.0 does), your 3.7L is tuned for 87 and using a higher octane won't gain you more than a few, if ANY, RWHP. Of course, there's the placebo effect, similar to how much faster my car is after a good cleaning and wax.
__________________
Rick
07 GT Prem: Alloy, MT, 3.55's, Steeda CAI w/Brenspeed tunes, FRPP Stingers, 275/40/18 Goodyear Eagle F1 A/S on SVT Cobras (OE GT500's), 14" shorty, Wheelskin side scoops & qtr window louvers, A-H rear window louvers, SHR honeycomb blackout panel, Sequentials, Hella Optilux Extreme XY fogs, Silverstars
06 V6: Legend Lime, Pony Package, 14" shorty, Sequentials, Hella Optilux Extreme XY fogs, Silverstars
Nuke is offline   Reply With Quote
Old 07-04-2013, 07:20 PM   #9
vixr
2nd Gear Member

 
vixr's Avatar
 
Join Date: Aug 2010
Vehicle: 2011 Mustang GT
Location: Florida
Posts: 259
Default

The computer on the 3.7 will advance timing until knock is detected by the knock sensors. The computer will bump the timing back to stop the knock. Higher octane fuel will not cause knock as soon as a lower octane fuel...will your 3.7 engine benefit from this? Of course it will...can you feel a difference from the drivers seat? Doubtful...

EDIT: when I say benefit, I mean your engine will have less knocking based on the total load you put on it
__________________
GODLESS HEATHEN


Eibach sportline kit, Boss 302 quad exhaust, BMR LCA, Boss 302 intake, BMR LCA re-locators, JLT carbon fiber CAI, BMR adj. panhard, FR 84.5 mm TB, Steeda adj. UCA, 302 strut brace, MM CC plates, 93 street tune, RTR chin splitter, MMD louvers

Last edited by vixr; 07-04-2013 at 07:38 PM.
vixr is offline   Reply With Quote
Old 07-04-2013, 08:06 PM   #10
JimC
Moderator
 
JimC's Avatar
 
Join Date: May 2006
Vehicle: 2013 MCA convertible
Location: Michigan
Posts: 5,202
Default

The 3.7 has similar adaptive programming to the 5.0 - we tried it out on the dyno and it picked up some RWHP and torque on the stock tune by using 93. Wasn't big (I can't remember the difference now) but was close to a tune for 93.

The car runs fine on 87 with no problems. Whoever told you that fuel economy suffers on the 87 octane doesn't know what he is talking about. I get the best MPG on the stock tune and 87 octane.
__________________

JimC is offline   Reply With Quote
Old 07-04-2013, 08:06 PM
MustangForums
Ford Mustang




Paid Advertisement

 
 
 
Reply

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

Forum Jump

Advertising

Featured Sponsors
Vendor Directory
New Sponsors
All times are GMT -5. The time now is 10:44 PM.

© Internet Brands, Inc.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Friendly URLs by vBSEO 3.5.2

This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company
Emails Backup