Fuel Grade discussion

[Pactola]

I just brought home a 2025 Platinum Max with the Stealth Performance Package with the HO engine.
The owners manual states that it runs fine on 87 octane but recommends at least 91 for best performance especially when it’s hot outside or when towing.
The dealership filled it up with regular 87 on delivery but they recommend using premium gas. I plan on continuing to use regular 87 octane on a regular basis but may switch to 91 when towing my 6000 pound boat.
Has anyone had any experience using both octane levels and noticed any difference in performance or gas mileage?

 

[Grrumpy]

Owners manual says it will run OK on regular, but recommends premium. That should tell you something right off the bat. Keep running regular around town I guarantee in the near future your engine will experience carbon build up and will start running like poop.
At least run mid-grade and if you do any towing or loading it up for long trips, use premium. And if at all possible use a top tier gas, meaning stay away from Happy Harry's Gas and Cannabis Emporium.....stick with brand name fuel's....Shell/Mobil/BP/Exon, ect.
You just spent gob's of $$$$$ on a vehicle so now is not the time to try and save a few $$$ on cheap gas.

 

[BMW2FORD]

Besides the octane, the other very important thing is if the fuel you purchase is top tier to avoid carbon build up and all sorts of problems. See the below link,

TOP TIER - High-quality Fuel Performance Standard - TOP TIER™

TOP TIER is developed and enforced by some of the leading automotive manufacturers and supplied by participating fuel retailers.

www.toptiergas.com

Besides being top tier, high octane is usually needed and good insurance sort of say when a vehicle is under high load or temperatures. Personally, I have a Costco account which is top tier and use premium since it’s not much more than regular at the station near me.

 

[jgmartin]

I did a lot of experimentation on a 6800 mile road trip and my findings were consistent with what I know from having tuned (ecu tuning) thousands of cars when I was in that business: it has a substantial effect, but the ecoboost controls are also basically magic and it’s totally safe. Coarse correction (predicted octane is what most obd2 tools call it on a ford) plus the electronic wastegates do the trick very effectively, just limiting load directly and pulling a bit of timing.

That said; you lose a lot of power (down to what ford would probably call the base level… ‘400hp’ or maybe less if you’re out west on 87) and the fuel mileage necessarily drops round 1-2mpg as the truck requires more torque demand to do the same work.

As noted above, within a single region the supplier and turnover often matters more than octane. Here in central FL Wawa 93 is trash, for instance. You just have to log and know your area if you really care to.

 

[BigOleFordFan]

Owners manual says it will run OK on regular, but recommends premium. That should tell you something right off the bat.

^^THIS^^

Hell, even my poor ole '011 runs way better on 91/93 than on 87....I realize it is a totally different vehicle, but just sayin

And for a brand new vehicle, I would have been cursing up a storm at the stealership clowns who delivered it to you with your very 1st tank of the low-est possible grade sludge that they buy at the lowest possible prices from the distributers.....

Almost as bad as the stealership where my son got his new Jeep Gran Cherokee, who tried to give it to him with ~about 1/4 of a tank of gas...I was like W.t.F.....I told the salesman, hey, this guy just spent $55K+ on this vehicle, so either fill it up asap, or they could cancel the deal & we would go somewhere else....

what a f*cked up way to treat a new customer

 

[VBreithaupt]

Every day driving, regular gas is fine. I have found towing my camper in the summer all throughout Michigan and the U.P. that it does run and get slightly better gas mileage on premium. Does it compensate for the extra cost? I figured it out to be worth it especially if you can get the gas at Costco or under a rewards discount.

 

[LostProV1]

This will be my first turbo vehicle, and at least right now, my plan is to run ethanol-free 91 in it all the time for max performance and protection. I'm lucky that I have several options for that nearby me.

 

[ZigZagFred]

We have used Top Tier 93 Octane gas since we bought our 2019 Limited in March of 2024. We are thankful that we can afford premium fuel. We highly recommend you do the same if you can afford it.

 

[Roland A]

I just brought home a 2025 Platinum Max with the Stealth Performance Package with the HO engine.
The owners manual states that it runs fine on 87 octane but recommends at least 91 for best performance especially when it’s hot outside or when towing.
The dealership filled it up with regular 87 on delivery but they recommend using premium gas. I plan on continuing to use regular 87 octane on a regular basis but may switch to 91 when towing my 6000 pound boat.
Has anyone had any experience using both octane levels and noticed any difference in performance or gas mileage?

It will run fine on 87 but mine runs quite a bit better on 93. Fun factor goes up quite a bit on 93 in Sport mode.I have had 3 Ecoboosts and they really shine when you “ drive it like you stole it”!

 

[Old Gearhead]

I have tried all grades of gas. I use the lowest only when I know I will be in town for a length of time (I live rurally). The drive is barely on the acceptable range. When I am traveling I always switch to the highest grade I can find and continue throughout the trip. It provides the best performance, a more enjoyable ride and the same gas mileage. Just recently I switched from 87 to mid grade and much more happier with in town experiences. My opinion - stick with mid grade in town and high grade when traveling

 

[BigOleFordFan]

“ drive it like you stole it”!

you forgot the end of that quote, which is: "from a red-headed stepchild", hahaha

 

[Expensedition]

BigOleFordFan....

Thanks for completing that quote... good laugh here.

My thoughts on fuel?

The best I can afford at the time, but often run a full tank of top tier to clean injectors, valves and piston crowns.

Right now, until we fix the mess in the gulf, buying any gas just sucks.

I have a Shell card, and maintain a platinum status. The 93 they sell is great for the cleaning it offers. Mobil, my next favorite is all about preventing wear.

V/r

SM

 

[JasonH]

Use top tier fuel always.

Regular or premium is your preference but you'll lose hp on regular because the engine pulls timing and reduces boost. Some people don't care but for me it was noticeable even at part throttle.

You'll also get slightly better mpg on premium. For me it was like 1 mpg, which offset half the cost of usi5the more expensive fuel.

I think regular can also cause more fuel dilution in the oil.

 

[LokiWolf]

This will be my first turbo vehicle, and at least right now, my plan is to run ethanol-free 91 in it all the time for max performance and protection. I'm lucky that I have several options for that nearby me.

Ethanol is GOOD for Turbo motors, NOT bad. Anybody who tells you different, has ZERO clue how Turbos work, and basic Chemistry.

Ethanol free will end up in some cases causing the ECU to pull more power than even 87(E10). Under high heat soak, Ethanol allows physical cooling in the intake and during combustion.

-Loki

 

[Fastcar]

I did a comparison some months ago and didn't see much difference in mpg perhaps 1 or 2 maybe as much as 3 on occasion mpg but I sort of attributed it to traffic speed and wind. Further I figure I'll keep this for another 50k and look for another. So I'm not really concerned about carbon build up or whatever. I agree there is a bit of performance difference on the SOP dyno but since it has the aerodynamics of a cinder block and it is a truck I can't worry about it. I'm also not towing with it. Also imo there is no mechanic in a can or a pump nozzle.