Can I put 87 octane in a 2018 Mustang GT? The manual does not state that premium fuel is required.

 

From the 2018 brochure: Horsepower and torque ratings achieved with 93-octane fuel.

So, you can run 87, but you will be down on power. Personally, I would just run premium.

https://www.ford.com/services/assets...tang&year=2018

 

I would re read the owner's manual and see if 87 is allowed before trying it. I have a '14 GT and the following is my personal experience. My owner's manual explicitly states that while 91 or higher is preferred, 87 is acceptable. 91 or higher is necessary in order to achieve the full 420 horsepower rating, but the loss when running 87 is negligible. 87 will generally drop power to around 408-410. This will show up on a dyno and probably on a drag strip or track, but certainly not when driving on the interstate running on cruise control. Even if the power were to drop to a measly 400 you wouldn't notice it when simply cruising along. My opinion is that if gas prices start rising and most of your driving is of a mundane nature there isn't any harm to the engine running 87. Depending on how many miles you drive in a year it could be a significant cost savings that you can use for other fun things. My girlfriend and I recently completed a 1,300 mile road trip and all I used was 87, no problem. I also have a track key and when using it 91 or better is REQUIRED. The point being that if you contemplate some sort of aftermarket tune, in most cases you will be unable to run 87 safely. One more thing, your gas mileage will probably drop slightly when using 87 since the PCM won't allow full timing advance. The loss in gas mileage is still small enough that you still come out ahead money wise. In the end how you use the car will pretty much dictate what octane fuel to run.

 

thank you for this post. Just two days ago I bought my first Mustang GT. 2014. While I was driving at home a 3 Hour Dr. from the dealership where I bought it online I called the dealership to ask him what gas was put in it. He had no idea I thought that was funny. Thank you for this informative post. I’m thinking about a cold air intake and possibly a Ford performance GT 500 muffler. And wheels and tires and that’s it.

Just bought this two days ago brought it home yesterday. 61 years old so I’m not gonna go teenager on this vehicle. I appreciate your opinions. Thinking cold air intake possible for performance Shelby GT muffler. Wheels and tires. That’s it. Friends of mine are talking about louvers for the back but I don’t know about that. Respect your opinions. Thank you for the add to this group looking forward to learning everything.I’ve been told a spoiler needs an upgrade. I love her and it’s a beast

 

Welcome to the forum!

Have a blast with your new pony!

 

Welcome to TMS. Looks like you found a nice car. Love my '14 and think you will enjoy yours too. Yes you are ok with 87 Octane as long as the car has not be modified. Does run best on a higher octane.

Start a new thread and give us info on you and your car. You can use that thread to keep us updated on your mod progress. Your car looks like a blank canvas, all set for your custom touches. Have fun with it and make it yours!

Surprised you did not Zombie this @houtex. It is three and a half years since the last post... :

 

Eh, I thought about it, but the truth is I've sorta made a 5 year rule, unless it's completely ridiculous. Too much of a good thing, y'know?

 

The Dealer where we bought ours said it was no problem to run 87 octane. Pretty sure that is what they filled the tank, so I will be interested to see if there is any noticable difference when I fill it with 91.

 

I have a 07 gt and I only run 91 or higher in it. I do notice the difference in power and also when I clean the throttle body. I also add a bottle of seafoam to the oil about 75 miles before I change it. Also once a month I would put some royal purple fuel max cleaner. Dont know it it does anything but makes me feel good to give my girl a mixed drink. Lol

 

Well, since we're sayin it, I've run all three through, and as you'd expect the power is down with the lower octane, and then the knocking happens at all but the top (91+) Little softer in the middle grade, but still there.

So Awesome gets premium only, because power and I don't like the knocking/rattling.