Premium vs regular gas - Mustang Evolution

Go Back   Mustang Evolution > 1979-2015 Mustang GT || Tech and Talk > 2011-2014 Mustang GT



Reply
 
Thread Tools Search this Thread
Please support our sponsors and let them know you heard about them here!
Old 06-10-2015, 04:00 PM   #1
Registered Member
Regular
 
scurfie's Avatar
 
Join Date: Mar 2015
Location: Lewisburg
Region: Pennsylvania
Posts: 449
Premium vs regular gas

Okay I know I know this has been beaten to death but I just think I need to share that I put 91 octane Sunoco gas in my GT and my mileage went DOWN. And not by a little. I am basing this mileage on the car's computer however so maybe that's a factor in this mix. My mileage started going right back up to 21mpg fairly quickly after filling with regular. Possibly a bad tank of gas? And as a side note, Ford specificity recommends regular octane. Am I not getting 435 HP unless I use 93 octane?

Thanks in advance! This is really bugging me.


Sent from my iPhone using Mustang Evolution
scurfie is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-10-2015, 05:44 PM   #2
Registered Member
Regular
 
Eric5oh's Avatar
 
Join Date: Nov 2014
Location: Kerper
Region: Florida
Posts: 328
Premium vs regular gas

As far as the lower gas mileage with high octane I'm not sure. But horsepower wise you won't get the most power out of the engine without 93.

2013 Sterling Grey GT/Brembo package/SR Performance lowering springs/J&M adjustable panhard bar/Roush axle back/AEM CAI
Eric5oh is offline   Reply With Quote
Old 06-10-2015, 05:48 PM   #3
ME Bloodhound
Staff
 
Soccerluvr4's Avatar
 
Join Date: Feb 2012
Location: Sacramento/Bay Area
Region: California
Posts: 14,672
Don't base it off the computer. Do the math by hand and see. And if you care that much about mpg you bought the wrong car.
__________________

Bullitt build paused pending graduation

HID end all thread
Soccerluvr4 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-10-2015, 06:18 PM   #4
Registered Member
Regular
 
scurfie's Avatar
 
Join Date: Mar 2015
Location: Lewisburg
Region: Pennsylvania
Posts: 449
Quote:
Originally Posted by Soccerluvr4 View Post
Don't base it off the computer. Do the math by hand and see. And if you care that much about mpg you bought the wrong car.
I know the 2015 GT is not a gas sipper, but I was surprised to get around 21mpg with mixed driving. To have it drop to 15-16mpg was a shock.
scurfie is offline   Reply With Quote
Old 06-10-2015, 06:51 PM   #5
Registered Member
Regular
 
Eric5oh's Avatar
 
Join Date: Nov 2014
Location: Kerper
Region: Florida
Posts: 328
Quote:
Originally Posted by scurfie View Post
I know the 2015 GT is not a gas sipper, but I was surprised to get around 21mpg with mixed driving. To have it drop to 15-16mpg was a shock.

You're computer is telling you something wrong if you're getting 21 city an any Mustang GT


2013 Sterling Grey GT/Brembo package/SR Performance lowering springs/J&M adjustable panhard bar/Roush axle back/AEM CAI
Eric5oh is offline   Reply With Quote
Old 06-10-2015, 06:53 PM   #6
Registered Member
Regular
 
mustangz's Avatar
 
Join Date: Aug 2013
Location: Virginia
Region: Virginia
Posts: 4,575
Quote:
Originally Posted by Eric5oh View Post
You're computer is telling you something wrong if you're getting 21 city an any Mustang GT


2013 Sterling Grey GT/Brembo package/SR Performance lowering springs/J&M adjustable panhard bar/Roush axle back/AEM CAI
I've actually gotten 21 in the city, driving regular, in alexandria. I did the math to check.
__________________
2013 GT Premium, Red Candy Metallic, Recaro seats, Electronic package, Strut tower brace, Sway bars, SHR flush mounted window louvers, RTR street-spec axleback exhaust, Ford Racing Boss 302 Side Exhaust, RTR wheels, 50/35% Window tint, Steeda black shorty antenna, and Ford OE Matte Hood Vents.
mustangz is offline   Reply With Quote
Old 06-10-2015, 07:03 PM   #7
Registered Member
Regular
 
Eric5oh's Avatar
 
Join Date: Nov 2014
Location: Kerper
Region: Florida
Posts: 328
Quote:
Originally Posted by mustangz View Post
I've actually gotten 21 in the city, driving regular, in alexandria. I did the math to check.

Crazy IMO. If so good for you man lol I can't get mine past 17 city


2013 Sterling Grey GT/Brembo package/SR Performance lowering springs/J&M adjustable panhard bar/Roush axle back/AEM CAI
Eric5oh is offline   Reply With Quote
Old 06-10-2015, 07:27 PM   #8
Registered Member
Regular
 
2014oxstang's Avatar
 
Join Date: Jun 2014
Location: East Longmeadow
Region: Massachusetts
Posts: 2,000
Quote:
Originally Posted by Eric5oh View Post
Crazy IMO. If so good for you man lol I can't get mine past 17 city


2013 Sterling Grey GT/Brembo package/SR Performance lowering springs/J&M adjustable panhard bar/Roush axle back/AEM CAI

Lol I can't even get mine to 17. 16.8 now for a hot minute. 95% city driving, 93 Sunoco


Sent from my iPhone using Mustang Evolution
2014oxstang is offline   Reply With Quote
Old 06-10-2015, 07:38 PM   #9
Registered Member
Regular
 
Dub9stang's Avatar
 
Join Date: Oct 2012
Location: Chicagoland
Region: Illinois
Posts: 278
I finally got up to 14...
Dub9stang is offline   Reply With Quote
Old 06-10-2015, 07:48 PM   #10
Registered Member

Regular
 
natestang07's Avatar
 
Join Date: Jun 2014
Location: Soap Lake
Region: Washington
Posts: 5,321
I get 21.5 with 90 percent highway lol
natestang07 is offline   Reply With Quote
Old 06-10-2015, 07:52 PM   #11
Registered Member
Regular
 
Eric5oh's Avatar
 
Join Date: Nov 2014
Location: Kerper
Region: Florida
Posts: 328
Quote:
Originally Posted by 2014oxstang View Post
Lol I can't even get mine to 17. 16.8 now for a hot minute. 95% city driving, 93 Sunoco


Sent from my iPhone using Mustang Evolution

Me saying 17 mpg Is being modest... I'm at 14 right now


2013 Sterling Grey GT/Brembo package/SR Performance lowering springs/J&M adjustable panhard bar/Roush axle back/AEM CAI
Eric5oh is offline   Reply With Quote
Old 06-10-2015, 09:32 PM   #12
Registered Member
Regular
 
2014oxstang's Avatar
 
Join Date: Jun 2014
Location: East Longmeadow
Region: Massachusetts
Posts: 2,000
Quote:
Originally Posted by Eric5oh View Post
Me saying 17 mpg Is being modest... I'm at 14 right now


2013 Sterling Grey GT/Brembo package/SR Performance lowering springs/J&M adjustable panhard bar/Roush axle back/AEM CAI

Damn, 16.9 is me ***** footing it around town too lol. No matter, like everyone else, I didn't buy it for the mpg's lol. Otherwise I would've bought a Prius


Sent from my iPhone using Mustang Evolution
2014oxstang is offline   Reply With Quote
Old 06-10-2015, 09:35 PM   #13
ME Bloodhound
Staff
 
Soccerluvr4's Avatar
 
Join Date: Feb 2012
Location: Sacramento/Bay Area
Region: California
Posts: 14,672
Check it by hand. Sometimes the computer can be off. Actually a lot of the time it can be off. Good old math by hand always works.


Bullitts are better than Bullets
__________________

Bullitt build paused pending graduation

HID end all thread
Soccerluvr4 is offline   Reply With Quote
Old 06-10-2015, 09:40 PM   #14
Registered Member
Regular
 
2014oxstang's Avatar
 
Join Date: Jun 2014
Location: East Longmeadow
Region: Massachusetts
Posts: 2,000
Quote:
Originally Posted by Soccerluvr4 View Post
Check it by hand. Sometimes the computer can be off. Actually a lot of the time it can be off. Good old math by hand always works.


Bullitts are better than Bullets

Dash says 250 to a tank? That sound accurate? I mean, how far off could it actually be?


Sent from my iPhone using Mustang Evolution
2014oxstang is offline   Reply With Quote
Old 06-10-2015, 10:30 PM   #15
Registered Member
Regular
 
Join Date: Mar 2013
Location: Salinas
Region: California
Posts: 7,415
A gallon of 91 octane fuel actually has LESS energy than a gallon of 87 octane fuel. This is due to the additives used to raise the octane rating.
It is not uncommon to experience a decrease in gas mileage when using high octane gasoline. A 25% drop is pretty excessive though. You would typically see a single digit decrease.
I agree with SL4, try the experiment again, but this time, hand calculate the MPG's.
straybullitt is offline   Reply With Quote
Old 06-10-2015, 11:30 PM   #16
ME Bloodhound
Staff
 
Soccerluvr4's Avatar
 
Join Date: Feb 2012
Location: Sacramento/Bay Area
Region: California
Posts: 14,672
I could understand if your mpg went down that much if you converted to E85 but just a few octane points, something isn't right.


Bullitts are better than Bullets
__________________

Bullitt build paused pending graduation

HID end all thread
Soccerluvr4 is offline   Reply With Quote
Old 06-11-2015, 04:12 AM   #17
Registered Member
Regular
 
scurfie's Avatar
 
Join Date: Mar 2015
Location: Lewisburg
Region: Pennsylvania
Posts: 449
Quote:
Originally Posted by Soccerluvr4 View Post
I could understand if your mpg went down that much if you converted to E85 but just a few octane points, something isn't right.


Bullitts are better than Bullets
I agree. So maybe the gas was "bad". I'll try 93 next and see what happens. Thanks for everyone's input btw. Like I said the shocker for me was getting over 20mpg in a new GT! That's not far from the average in my old Toyota!
scurfie is offline   Reply With Quote
Old 06-11-2015, 05:47 AM   #18
Registered Member
Regular
 
14 5.0's Avatar
 
Join Date: May 2014
Location: Parkland
Region: Florida
Posts: 45
I'm only getting 12 miles per gallon with city driving. I'm sure it will get better once the engine breaks in. She only has 300 miles.
14 5.0 is offline   Reply With Quote
Old 06-11-2015, 09:27 AM   #19
Registered Member
Regular
 
KARgt13's Avatar
 
Join Date: Nov 2012
Region: Pennsylvania
Posts: 720
Isn't the stock tune based on 91? 91 and 93 are both called Premium.
KARgt13 is offline   Reply With Quote
Old 06-11-2015, 09:42 AM   #20
Registered Member
Regular
 
mustangz's Avatar
 
Join Date: Aug 2013
Location: Virginia
Region: Virginia
Posts: 4,575
Quote:
Originally Posted by KARgt13 View Post
Isn't the stock tune based on 91? 91 and 93 are both called Premium.
Ford rates the engine using 93.
__________________
2013 GT Premium, Red Candy Metallic, Recaro seats, Electronic package, Strut tower brace, Sway bars, SHR flush mounted window louvers, RTR street-spec axleback exhaust, Ford Racing Boss 302 Side Exhaust, RTR wheels, 50/35% Window tint, Steeda black shorty antenna, and Ford OE Matte Hood Vents.
mustangz is offline   Reply With Quote
Old 06-11-2015, 09:47 AM   #21
Registered Member
Regular
 
KARgt13's Avatar
 
Join Date: Nov 2012
Region: Pennsylvania
Posts: 720
Quote:
Originally Posted by mustangz View Post
Ford rates the engine using 93.
Oh okay, thanks
KARgt13 is offline   Reply With Quote
Old 06-11-2015, 12:49 PM   #22
Registered User
Newbie
 
Join Date: May 2015
Location: Russellville
Region: Arkansas
Posts: 14
I have a 2015 GT stick shift with 3500 miles. I have never run anything other than 93 octane, ethynol free. Getting 19 in town, over 25 average on highway, running 75-78 mph. Sounds incredible, but all true.
respolt52 is offline   Reply With Quote
Old 06-11-2015, 01:49 PM   #23
Registered Member
Regular
 
scurfie's Avatar
 
Join Date: Mar 2015
Location: Lewisburg
Region: Pennsylvania
Posts: 449
Quote:
Originally Posted by respolt52 View Post
I have a 2015 GT stick shift with 3500 miles. I have never run anything other than 93 octane, ethynol free. Getting 19 in town, over 25 average on highway, running 75-78 mph. Sounds incredible, but all true.
We can't get ethanol free where I live.
scurfie is offline   Reply With Quote
Old 06-11-2015, 02:00 PM   #24
Registered Member
Regular
 
Sterlingbeast5.0's Avatar
 
Join Date: Nov 2013
Location: Naples, FL
Region: Florida
Posts: 1,654
SPG means more than MPG. I get 16.4 and that was allot more highway than usual lately. I am not sure about MPG difference based on octane but everyone is right the horsepower is better and that leads to more SPG
__________________
Brembo Pkg, Paxton SC, ID1000's, JMS BAP, Boss IM, JLT CAI, Lund Tuned, Tremec T56 swap, Black Pype Bombs, Pypes LT Headers H-Pipe, McLeod RXT Twin Clutch & LW Flywheel. Alum. DS, MGW Shifter, BMR adj. Panhard, UCA & LCA's, Eibach Pro Damper, Sportline Springs, MMD Louvers, Roush splitters, RTR decklid and surround, CDC Grille, Staggered 20" ACE Alloy Driven, Trufiber Hood.
Sterlingbeast5.0 is online now   Reply With Quote
Old 06-11-2015, 02:13 PM   #25
Registered Member
Regular
 
Jbone007's Avatar
 
Join Date: Mar 2015
Location: Oceanside
Region: California
Posts: 435
I am at 17.4 now was averaging around 14 when new. I have about 12k on her now, (91 octane)
Jbone007 is offline   Reply With Quote
Old 06-11-2015, 03:38 PM   #26
Registered Member
Regular
 
rockhillgt's Avatar
 
Join Date: Mar 2014
Location: rock hill
Region: South Carolina
Posts: 344
i get an average of 16.8 Paxton charged
__________________

rockhillgt is offline   Reply With Quote
Old 06-11-2015, 04:02 PM   #27
Registered Member
Regular
 
Mlp07's Avatar
 
Join Date: Dec 2012
Location: Weslaco
Region: Texas
Posts: 425
You guys with 20mpg on city must have 3.31s or have automatics, if I really really baby it I get 17-18 mpg.


Sent from my iPhone using Mustang Evolution
Mlp07 is offline   Reply With Quote
Old 06-11-2015, 04:20 PM   #28
Registered Member
Regular
 
mustangz's Avatar
 
Join Date: Aug 2013
Location: Virginia
Region: Virginia
Posts: 4,575
Quote:
Originally Posted by Mlp07 View Post
You guys with 20mpg on city must have 3.31s or have automatics, if I really really baby it I get 17-18 mpg.


Sent from my iPhone using Mustang Evolution
Even with my auto, I rarely get 20 in the city, usually 14-17.
__________________
2013 GT Premium, Red Candy Metallic, Recaro seats, Electronic package, Strut tower brace, Sway bars, SHR flush mounted window louvers, RTR street-spec axleback exhaust, Ford Racing Boss 302 Side Exhaust, RTR wheels, 50/35% Window tint, Steeda black shorty antenna, and Ford OE Matte Hood Vents.
mustangz is offline   Reply With Quote
Old 06-11-2015, 04:40 PM   #29
Registered Member
Regular
 
Mlp07's Avatar
 
Join Date: Dec 2012
Location: Weslaco
Region: Texas
Posts: 425
Quote:
Originally Posted by mustangz View Post
Even with my auto, I rarely get 20 in the city, usually 14-17.

I usually get 15 only on city, but with both normal driving and having some fun.


Sent from my iPhone using Mustang Evolution
Mlp07 is offline   Reply With Quote
Old 06-11-2015, 04:58 PM   #30
Registered Member
Regular
 
mustangz's Avatar
 
Join Date: Aug 2013
Location: Virginia
Region: Virginia
Posts: 4,575
Quote:
Originally Posted by Mlp07 View Post
I usually get 15 only on city, but with both normal driving and having some fun.


Sent from my iPhone using Mustang Evolution
Roughly the same with me.
__________________
2013 GT Premium, Red Candy Metallic, Recaro seats, Electronic package, Strut tower brace, Sway bars, SHR flush mounted window louvers, RTR street-spec axleback exhaust, Ford Racing Boss 302 Side Exhaust, RTR wheels, 50/35% Window tint, Steeda black shorty antenna, and Ford OE Matte Hood Vents.
mustangz is offline   Reply With Quote
Old 06-11-2015, 05:20 PM   #31
Registered Member
Regular
 
KryptonKnight's Avatar
 
Join Date: Feb 2007
Posts: 113
Octane is short for "octane rating" which is used as an index of a fuel's ability to resist engine knock (the pre-ignition caused by the heat of compression under load or at high compression ratios causing the fuel to ignite before TDC and the spark plug fires. It's like trying to make the crank to turn in reverse. So the power stroke tooo early and that is the knock). It is highly combustible but is not actually associated with MPG. Confused yet?
__________________

CAI,6pt.Cage,FRPPSprings,Raptor,UDP,Hurst,SiliconeHoses,BossStrutBar,LoudMouths,Plenum,Cam,Brake,Battery,StrutCovers,FRPP PC.ValveCovers,Chin Spoiler,Hood Scoop&Pins,painted 10"Stripes & Pins,EleanorGrill,Chin Spoiler,"C" Scoop,1/4 Side Scoops,Rear Fascia,PJ Rear Louvers,Roush Skirts & Rear Wing,Triple Pod & Gauges,CF Dash,2010Projector lights,2014Taillights, Real Carbon Fiber full kit,19" 2014 GT rims.
KryptonKnight is offline   Reply With Quote
Old 06-11-2015, 06:21 PM   #32
Registered Member
Regular
 
scurfie's Avatar
 
Join Date: Mar 2015
Location: Lewisburg
Region: Pennsylvania
Posts: 449
This is so weird. My 22hp garden tractor running 91 octane is using much less gas. I have a gas gauge and I am very very familiar with how much gas I go through with each mow. Now the owners manual specifically says to use regular octane gas. So my Mustang gets worse, and my good old tractor gets better gas mileage. Go figure.
scurfie is offline   Reply With Quote
Old 06-11-2015, 09:18 PM   #33
Registered Member
Regular
 
Compstall's Avatar
 
Join Date: Jun 2012
Location: Tacoma, WA
Region: Washington
Posts: 1,162
It's always great to be at the forefront of new information. I'm glad this thread is here.


Sent from my iPad using Mustang Evolution
__________________
- Brent
'11 GT Kona Blue Brembo
"Measure with micrometers, mark with a scribe, chop with an axe"
"I'm not new to driving. I've been doing it for a couple of years now." - Aphex
Compstall is offline   Reply With Quote
Old 06-17-2015, 01:30 AM   #34
Registered Member
Regular
 
Join Date: Jun 2015
Location: san diego
Region: California
Posts: 19
every gas station i go to is always 91 never seen 93 yet
Saint Patron777 is offline   Reply With Quote
Old 06-18-2015, 06:27 PM   #35
Registered Member
Regular
 
randyGT's Avatar
 
Join Date: Jun 2015
Location: Garden Grove
Region: California
Posts: 54
Quote:
Originally Posted by Eric5oh View Post
You're computer is telling you something wrong if you're getting 21 city an any Mustang GT


2013 Sterling Grey GT/Brembo package/SR Performance lowering springs/J&M adjustable panhard bar/Roush axle back/AEM CAI
That's not true at all. My 2015 GT 5.0 gets 27 mpg highway (long trips) and 20-21 in Orange county California driving any day (that I don't stick my foot in it).
randyGT is offline   Reply With Quote
Reply

Lower Navigation
Go Back   Mustang Evolution > 1979-2015 Mustang GT || Tech and Talk > 2011-2014 Mustang GT

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 On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
recaro leather seat option - are rears the same as regular premium seats? paradigm 2011-2014 Mustang GT 0 07-18-2013 03:37 PM
Switch from premium to regular gas NEED HELP Nick Proben 1979-1995 Mustang GT 41 04-27-2013 08:02 PM
regular or premium?? richgangsta41 2011-2014 Mustang GT 13 01-27-2013 09:52 AM
Regular or premium Whitelightning 2011-2014 V6 Mustang 33 06-30-2012 11:55 AM
Burning regular gas in a 5.0 jimbullit 2011-2014 Mustang GT 35 02-22-2011 11:00 AM

» Like Us On Facebook



05:01 PM


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0

MustangEvolution.com is in no way associated with or endorsed by Ford Motor Company.