Octane curiosity - anybody running 87 octane?

[Dominant1]

Sunoco 93 + a bottle of Lucas octane booster in every tankful on the street, at the track 93 plus Vp octanium unleaded..my .car runs great.

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[stanger1]

Where I am located and our gas, which 91 octane is the highest we have, even running 91, I will see + knock , which is not good. I must use Boostane, preferred. If I don't, +, which is bad.
With Boostane, 3-4 ounces to 15 gallons and my ngauge shows me - negative Knock and is adding 3-4 degree's of timing.
- or negative knock is good and adding timing.
So if one is using 87, i would bet the Knock sensors are seeing + Positive knock and pulling timing.

 

[shogun32]

So if one is using 87, i would bet the Knock sensors are seeing + Positive knock and pulling timing.

does your 'seeing knock' with 87 hold at less than 30% throttle where casual driving occurs?

 

[stanger1]

If you were to drive the car mildly, which I can not do, you would probably be ok, but it a 400+hp car, why go cheap on the gas?
For me, I have a 17 RS3, so it is FI. VMP tuned 730hp crank.
But even trying to stay out of boost, when in a higher torque situation, without Boostane, I could sometimes see + knock.
For me, I drive this type of car for the power, performance, etc and will alway put the best of everything in and on the car.

 

[Stang55]

If you were to drive the car mildly, which I can not do, you would probably be ok, but it a 400+hp car, why go cheap on the gas?
For me, I have a 17 RS3, so it is FI. VMP tuned 730hp crank.
But even trying to stay out of boost, when in a higher torque situation, without Boostane, I could sometimes see + knock.
For me, I drive this type of car for the power, performance, etc and will alway put the best of everything in and on the car.

I was tuned with an SCT X4, can I view the knock and spark if I plug it in?

 

[stanger1]

PS.
I have never put 87 octane in any of my Mustangs. I know for stock, the manual says you can, but.
if your going to put 87 in the car, just buy something else to drive. Just my opinion!

 

[shogun32]

I was tuned with an SCT X4, can I view the knock and spark if I plug it in?

absolutely but I think a plain ol' OBD logger can see that info as well.

 

[stanger1]

I think the SCT can do it, but i never spent the time to try it and figure it out.
Somebody on here may chime in on that.
Ngauge is super easy.

 

[Stang55]

absolutely but I think a plain ol' OBD logger can see that info as well.

thanks!

 

[Louk]

Out of curiosity, I loaded up w/a tank of Sunoco's good ol' 87 octane today in the '19. Saved myself more than $7 for the 11 gallons over their 91 octane's price. Would've been even more if I had gone as I often do w/their 93 octane.

Doesn't sound like much but over time that could add up, especially since I tend to fill up twice per week. It could mean more than $60 a month, or almost $700 a year, more if I compared to 93! That's six months of auto insurance costs for me.

Mindya, my car is a daily driver, not a track or race car. I'm not looking for ultimate performance/HP, etc. Anyway, the car ran fine. In the routine powerband I normally drive in, I felt zero difference in engine performance. And amazingly, I had to do some highway miles and got my highest mileage yet- 28.6 MPG cruising at 77 MPH.

So there ya go- that's my experiences from today.
Lee

As others have said costco/sams all the big discount stations are much closer to a .30 cent difference which is between 3-4 dollars a fill up. your 700 number would quickly drop to 300-400. Understandably its still a savings of a few hundred dollars a year but then again why pay the thousands of dollars premium for a 480 HP car to feed it fuel it "can" run on and not the good stuff.

I am not sure if its been said yet but in city driving premium will yield slightly higher MPG and highway regular will get slightly higher MPG

If gas savings and not caring about the performance why not save the dough and get an ecoboost? Thats my take on it. I bought the car to go fast and have fun.. Its about Smiles Per Gallon not Miles Per Gallon.

 

[Stang55]

So giving up a few horsepower to save $.50-1.00 a gallon means you shouldn’t drive a Mustang?

Just for the record- Ford put a tremendous amount of time and energy into making these 12:1 cars run on 87 octane. Its not a big deal to run 87 in them and will have zero downside besides giving up a few HP and quite a bit of low range torque.

Gas is cheap at the moment but when it does go back up more people are going to be forced to buy 87 as the differential between the two rises.

As my tuner would say: "All pump gas is shit" LOOOL

 

[sk47]

So giving up a few horsepower to save $.50-1.00 a gallon means you shouldn’t drive a Mustang?

Hello; My mother had a Pontiac V-6 which was made to run on 87 octane. She would fill up with the premium (higher octane) fuel because she thought it is better fuel. Never could talk her out of that. Lots of money wasted. This was before the more current control systems.
I had an 1989 Ford F-150 with dual fuel tanks. I kept one tank filled with 87 octane and the other with 91 or 93. Cruising around it ran well on 87. With a load it ran better with the higher octane fuel. I had the ability to switch.
It is my understanding with todays electronic control systems for critical things such as timing, that the engines can digest the lower octane fuel without damage. Then if you put higher octane fuel the engine is adjusted and makes more HP. With lower octane fuel you lose a few HP compared to higher octane fuel is suppose to be the difference.

Now there are two things I think of when considering which fuel to run. In an older( higher mileage) engine where there can be carbon deposits it might be wise to use the higher octane fuel. Those carbon deposits can retain enough heat to pre-ignite the lower octane fuel.
The other thing is how far a manufacturer will go to make a car appear to have lower operating costs. I have not yet bought into the 7,000 to 10,000 mile oil change interval for example.

One of the things that appeals to me in the V-8 Mustang is to be able to use 87 octane fuel. I passed on the Subaru BRZ and Toyota 86 because they require premium fuel. Same for the Miata after the year 2000 model. I do not plan to track nor drag race if I get a mustang and do plan to run the octane the factory says is OK. Beyond the speculation is there any known reason why the 87 octane actually is harmful to use??

 

[shogun32]

will have zero downside besides giving up a few HP and quite a bit of low range torque.

people bitch plenty about 'no torque' below 4000 RPM already. And it's "no downside" to neuter it even more? But sure, driving around town like any adult with a modicum of sanity and impulse control 87 is just peachy. It'll get you from A to B just fine.

Gas is cheap at the moment but when it does go back up more people are going to be forced to buy 87 as the differential between the two rises.

nope, they'll either drive their cars even less - what percentage park their cars for 4 months or only drive it when it's sunny and over 60 and on weekends? Or face the music that they bought a high performance V8 and shrug off the gasoline cost as no more a nuisance than a gnat is to an elephant. I mean you gotta have a screw loose to buy any V8 if fuel costs matter a damn. I'd still drive the V8 as much as I do now even if it was $8/gal for 93.

Short of the Arab states USA is one of the cheapest places for gasoline.

 

[spectreman]

WHILE I APPRECIATE EVERYONE'S INPUT, I ALWAYS FIND IT INTERESTING/FUNNY HOW, WHEN ONE POSTS A TOPIC OF THIS NATURE, SO MANY PEOPLE TAKE OFFENSE TO THE TOPIC, AS IF IT AFFECTS THEM PERSONALLY WHEN, CLEARLY, IT DOES NOT. NO ONE IS FORCING ANYONE TO PUT IN ANY PARTICULAR OCTANE, OR BRAND OF GAS IN YOUR CAR. RUN IT AS YOU SEE FIT.

IT WAS PURELY A THEORETICAL OR EXPERIENTIAL QUESTION & SEEKING THE INPUT OF THOSE WHO MAY HAVE RUN 87 AND INSTEAD I GET "INTERNET ENGINEERS" WHO KNOW BETTER THAN THE FORD FOLKS, YA KNOW- THE ENGINEERS WHO ACTUALLY DESIGNED ALL THE SYSTEMS WITHIN THE 5.0- WHO HAVE SAID IT'S FINE TO RUN THIS ENGINE ON 87.

IF YOU WANT TO RUN 87, 91 OR 93, WHATEVER, FINE, SPEND YOUR $$ AS YOU SEE FIT. I'M NOT TELLING YOU NOT TO. I WANTED TO SEE WHAT- IF ANY- DIFFERENCES WOULD OCCUR IF I TRIED 87. MY LIMITED, ANECDOTAL RESULTS SO FAR HAVE BEEN ACCEPTABLE "TO ME." YMMV.

IF YOU'RE OFFENDED BY THAT, THEN LOG OFF THE THREAD. IF YA'LL GOT $700 A YEAR TO FLUSH DOWN THE TOILET SO YOU CAN BRAG ABOUT THOSE EXTRA 5-15 HP THAT YOU LIKELY CAN'T EVEN FEEL AT THE TOP END OF THE REV RANGE, THEN GOD BLESS YA'LL AND ENJOY IT. ME, I'M GOING TO KEEP EXPERIMENTING TO SEE WHAT TYPE OF RESULTS I GET.

AND FOR YOU COSTCO GAS LOVING FOLKS, THERE'S NO COSTCO W/IN 15 MILES OF MY HOUSE BUT THANKS FOR THE TIP.

 

[shogun32]

F YA'LL GOT $700 A YEAR TO FLUSH DOWN THE TOILET SO YOU CAN BRAG ABOUT THOSE EXTRA 5-15 HP THAT YOU LIKELY CAN'T EVEN FEEL AT THE TOP END OF THE REV RANGE, THEN GOD BLESS YA'LL AND ENJOY IT

a little shouty, are we?

Nobody 'feels' HP, they feel torque and that's where the big impact is.

You asked a 'loaded' question and got sensible answers as well as snide ones. It's the Internet. Who cares what forum jockies say anyway? If the manual says you can run 87 that's the definitive answer. We/you pissed away 35-50 grand on a completely impractical 4-wheel conveyance and so it naturally follows that the fuel bill doesn't even register as a consideration.

Not seeing how a Costco etc. a mere >15 miles away is some kind of great difficulty. Do you live at the wrong end of a goat track where gramps on a walker makes better time than you can because of traffic?

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