87 octane vs 91 octane

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Scottydoggs

Full Access Member
Joined
Dec 16, 2017
Posts
2,515
Reaction score
3,653
Location
NJ
audible ping and knock retard are not really the same thing.

knock retard pulls timing to keep the knock down. ( trying to save its self) on a boosted set up kr is what chips yer pistons up. then you own a paper weight lol

my regal is supercharged, for every degree of kr it gets, it pulls two degrees of timing, so get like 8º kr and you just lost 16º timing, and yup, car falls on its face hard.

funny part is thats a true event, back when it was all stock, 8º kr factory tune. no mods. oh, and it ran 16º wot timing stock tune, so it was neg degrees timing at times. thanks GM lol
 

Scottydoggs

Full Access Member
Joined
Dec 16, 2017
Posts
2,515
Reaction score
3,653
Location
NJ
you need a live scanner to scan for knock too. the torque app works very well for it.

higher octane, generally, less kr. why e85 adds like free hp almost, its got a much higher octane rating, so you can run more timing in your tune.
 

Vector

Full Access Member
Joined
Sep 18, 2013
Posts
234
Reaction score
52
Location
South Florida
James I on the road this week so tried 2 tanks of 93 Exxon-Mobil. I was down to 50 miles left to empty when I tried my first tank of 93. I generally never let the gas get that low. I did not get better mileage but I have zero complaints on the mileage am I getting. I did not notice any more power out my 5.3. A least not that I noticed.

Some people [not you] think there are magic powers when you use 93 octane. I am back to running 87.

I generally use the same octane all the time so the engine does not have to adjust to different octane levels.

All that is just me. To each their own.

I use to run 87 in my 2007 Sub (with a 5.3) without ever having a problem.

Now that I have the large engine with the 2015 Escalade I try to use 93 unless it is some ungodly price. I'll add enough 87 to keep me going until I can get to a Costco where prices are as much as $.30 less per gal.
So I cannot say I've ever run just straight 87 in it, as it is blended with the 93 still in the tank. However thus far, when I have added say 10 gallons of 87, I have not noticed any problem. As to mileage and get up and go, I have not really checked that.
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
19,145
Reaction score
25,167
Location
Treasure Coast, Florida
Not that I know of.
It is not badged that way, but I imagine Caddy's wouldn't carry that badge even if it were (for the upscale cosmetic look).

I must say I am still more of a Sub guy, but certain things on this Escalade are nice.

Even if there are no badges, it would have a yellow gas cap if it were. They sure are nice! That is what sets them apart!

I mentioned E85 as an even less expensive alternative if your motor can burn it.
 

Scottydoggs

Full Access Member
Joined
Dec 16, 2017
Posts
2,515
Reaction score
3,653
Location
NJ
I mentioned E85 as an even less expensive alternative if your motor can burn it.


i wish we had e85 here in NJ, id have been on it years ago.

and then id take my stock regal injectors ( cause they are larger then stock 5.3) and use them in the tahoe and run that pig on corn too.

have tuner in hand, you can pretty much do as you like with fuel, timing and so on.

but no corn for me, best i can do is meth/water injection. its almost as good for raising the octane rating of your fuel. and cooling the blower down. i have a ic as well, cool engine, hit the starting line at the track one pass, no way your touching the blower. add meth, i can give it a long ass kiss if i wanted to, its only warm at best now.
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
19,145
Reaction score
25,167
Location
Treasure Coast, Florida
i wish we had e85 here in NJ, id have been on it years ago.

and then id take my stock regal injectors ( cause they are larger then stock 5.3) and use them in the tahoe and run that pig on corn too.

have tuner in hand, you can pretty much do as you like with fuel, timing and so on.

but no corn for me, best i can do is meth/water injection. its almost as good for raising the octane rating of your fuel. and cooling the blower down. i have a ic as well, cool engine, hit the starting line at the track one pass, no way your touching the blower. add meth, i can give it a long ass kiss if i wanted to, its only warm at best now.

My first car was a '79 Regal Sportcoupe with the carbureted V6 Turbo. It had a defunct water injection system that I got going again and would add rubbing alcohol to the water in the tank, had these little jets to change out for more or less. It allowed me to run a few more pounds of boost, from 8 to 11 I think but that was a long time ago. Fun stuff.
 

Scottydoggs

Full Access Member
Joined
Dec 16, 2017
Posts
2,515
Reaction score
3,653
Location
NJ
My first car was a '79 Regal Sportcoupe with the carbureted V6 Turbo. It had a defunct water injection system that I got going again and would add rubbing alcohol to the water in the tank, had these little jets to change out for more or less. It allowed me to run a few more pounds of boost, from 8 to 11 I think but that was a long time ago. Fun stuff.


oh for sure. i was on a 3.2 pulley and 14º wot timing. all she would take with out knocking like a ****** bed lol

added meth kit, dropped to a 2.8 pulley, and got the tune to take 21º wot finally since i got a hpt tuner. for some reason the DHP was not getting the job done so well. i worked it to 19 wot, got 3 more with hpt.

had a friend in the car the other day, dropped the hammer and he locked up grabbed the JC bar for dear life till i let off lol hes not had a hell ride since its been re tuned to 21º.

odd thing is ive heard tails of running super aggressive timing, from the bottom up will kill kr. so thats what i tried. on the line brake boosting it at the track i used to be at 14, now 21. and now it just stays at 21 through the whole rpm range, even after a shift, still 21. no kr but a blip at the shifts thats no higher then one full degree, i can so deal with that little bit.

my timing file graph looks like the mountain the guy from close encounters of the third kind was building the whole movie lol

003.jpg
 

Forum statistics

Threads
129,112
Posts
1,810,629
Members
92,199
Latest member
Romeroman64
Top