Premium fuel or Regular? GT Coyote V8

DukeGaGa · Dec 16, 2017

well, for my 2018 I'm only giving it 93 and above from shell.

DickR · Dec 16, 2017

From the owner manual:

Your vehicle is designed to operate on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87. We do not recommend these fuels.
For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer. See Towing a Trailer.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.
Do not use any fuel other than those recommended because they could lead to engine damage that will not be covered by the vehicle Warranty.
Note: Use of any fuel other than those recommended can impair the emission control system and cause a loss of vehicle performance.
Do not use:
Diesel fuel.
Fuels containing kerosene or paraffin.
Fuel containing more than 15% ethanol or E85 fuel.
Fuels containing methanol.
Fuels containing metallic-based additives, including manganese-based compounds.
Fuels containing the octane booster additive, methylcyclopentadienyl manganese tricarbonyl (MMT).
Leaded fuel, using leaded fuel is prohibited by law.
The use of fuels with metallic compounds such as methylcyclopentadienyl manganese tricarbonyl (commonly known as MMT), which is a manganese-based fuel additive, will impair engine performance and affect the emission control system.
We recommend Top Tier detergent gasolines to help minimize engine deposits and maintain optimal vehicle and engine performance. For additional information, refer to www.toptiergas.com.

Keep in mind that most of the West doesn't have 93 Octane. I use 93 simply because I autocross the car and want the maximum available power . . . which is really silly because the amount of full throttle time in an autocross Mustang V-8 is minimal compared to part throttle time. :-)

HeavyMetalMonk · Dec 16, 2017

Hey OP, I think I must know you from like....87 other forums.

Anyway, I'll be running e85 and 91 in mine.

EvilleGT · Dec 16, 2017

This should sign some real light on the subject as the test actually used a Mustang GT.

HoosierDaddy · Dec 16, 2017

WildHorse said:
my 2017 Mustang GT, tt only gets 94 octane. I didn't buy it for fuel economy reasons.

I also didn't buy a Mustang for fuel economy. That's why I only drive at WOT in the lowest possible gear. Anything less is just throwing away performance you paid for up front. It's just stupid to drive around getting hundreds of fewer HP than you paid for. I do use 87 octane, though.

Swamp-Yankee · Dec 16, 2017

On a slightly different topic will we ever again have a Mustang whose fuel tank holds 22 gallons? Or anything more than the typical 16 or so gallons?

Swamp-Yankee · Dec 16, 2017

By the way, I also voted “pie” - mmmmmm delicious pie. ;)

WildHorse · Dec 16, 2017

HoosierDaddy said:
I also didn't buy a Mustang for fuel economy. That's why I only drive at WOT in the lowest possible gear. Anything less is just throwing away performance you paid for up front. It's just stupid to drive around getting hundreds of fewer HP than you paid for. I do use 91 octane, though.

A7X · Dec 16, 2017

I get 91 - no ethanol. Our 87 has up to 10% ethanol

foqus · Dec 17, 2017

EvilleGT said:
This should sign some real light on the subject as the test actually used a Mustang GT.

For those who don't have 13 minutes to waste and just want the quick result without all the detail:

For the 2017 Mustang 5.0, power improvement is +2.3% on average and up to +8% peak with premium vs regular fuel, torque is up 1.8%, and average improvement in fuel economy is 3.2%, with a peak of 4.3% better fuel economy using premium.

Then the guy concludes by saying it's not worth it because premium fuel costs more.

div2 · Dec 17, 2017

I run only Top Tier 93 octane in everything but the Wrangler; if I do get a GT it will get only Top Tier 93 octane as well.

tom_sprecher · Dec 17, 2017

HoosierDaddy said:
I also didn't buy a Mustang for fuel economy. That's why I only drive at WOT in the lowest possible gear. Anything less is just throwing away performance you paid for up front. It's just stupid to drive around getting hundreds of fewer HP than you paid for. I do use 87 octane, though.

:lol:

From the video I had not realized the % increase of the price of premium over regular in the past several years. Interesting and I want for find out why.

The only time I have put premium in my car was for some dyno pulls. Other than that I run regular because I'm cheap and seek out good value in my purchases. It's also why I bought a Mustang. At $40k loaded it is a cheap car with a lot of bang for the buck.

abie915 · Dec 17, 2017

The manual says use regular, so that's what I use

tom_sprecher · Dec 17, 2017

Everything I said above might go out the door since I am now looking at doing the Power Pack 2 which requires at least 91. :doh:

JohnD · Dec 17, 2017

A7X said:
I get 91 - no ethanol. Our 87 has up to 10% ethanol

Yes, and I saw recently were the WindBag and her gang of eager money spenders want to double that. Won't that be fun!

Premium fuel or Regular? GT Coyote V8

Mustang GT fuel?

Super

Regular

Pie

DukeGaGa

Well-Known Member

DickR

Well-Known Member

HeavyMetalMonk

Well-Known Member

EvilleGT

Well-Known Member

HoosierDaddy

Well-Known Member

Swamp-Yankee

Active Member

Swamp-Yankee

Active Member

WildHorse

N/A or GO HOME

A7X

Well-Known Member

foqus

Well-Known Member

div2

Active Member

tom_sprecher

Living Race Car Free

abie915

Well-Known Member

tom_sprecher

Living Race Car Free

JohnD

Legend in his own mind