chacotaco=moron im sorry but. heh engine getting used to an octane HAHAHA. i wish my car was equipped with an ADVANCED AI.

 

(no name calling here) but the term 'getting used to' is kinda funny and definitely would not be considered a technical term. But chacotaco, if this statement had any basis in fact, how long would it take (in miles) for an engine to 'get used to' 93 octane? And where did you hear something that leads you to believe that this might actually be true. Just curios, I'm sure you got this from somewhere.

 

Either you are on the high octane table, or the low octane table. I just had my car tuned yesterday, and the guy before me had run the low octane and due to a knock sensor reading, it had defaulted to the low octane table. Timing was 10 degrees behind, making it run worse and get worse mileage.

Oh and my car didn't argue to keep the low octane. Guess it was tired of being "used to" some 89 and needed some "strange".

 

LS1 recommended octane is 91. 93 will provide no benefit on a stock or lightly modified, stock compression level vehicle.

Any perceived benefit going from 91 to 92 or 93 on a stock vehicle is more likely to have been from a bad batch of gas than any actual performance gain.

Even when I've been stuck using seasonal blends with ethanol in 91 octane form my car drove and produced the same mileage as when I had access to 93 octane in the East.

Dont' use 87 or 89 unless you're in a pinch...I've been in places in New Mexico and other Southwestern states where only 85 and 86 were available and 87 was a lucky find!

 

its like that here too, most gas stations sell 87,89,93, theres only like one or two that sell 91 octane, and a couple places that sell 100 octane, and thats about it.

 

My car is doomed, it has been running on premium for a long time....

So based on your logic, if I were to run 95 octane for 5 yrs of my cars life, then go to...91 for example, it would struggle to run properly because it will have learned (it believes) that it needs 95 to run? Crazy people at GM must have slipped this one by us all. And HPTuners adds the low octane table just to sell units.

 

I run 91 and have never had an issue. This higher octane=more power myth has been around forever. If you think you feel a difference when you run 93 then spend the extra money on it. It's your car and your money.

 

no, no, no, you're not getting what i'm saying. later in your engine's life, you can expect your car to ping. who knows how long it'll take. one thing's for sure, unless you blow the engine up, at somepoint it'll develop ping. well, the solution to the ping is to raise the octane, right? right. well, running 93 from the get-go will not prolong the ping as the octane actually shows no benefit as the engine does not need it. since going 93 octane over 91 octane shows no benefits, chances are, the ping will develop at roughly the same time. if you go from 91 to 93, it'll help, if not solve the issue. if you develop ping running on 93, you'll have nowhere to go.

by nowhere am i saying that your engine has a brain and will only function on that specific octane. what i said was, when ping develops running 93, you'll have no cushion but if it develops while you run 91, you can up it to 93 and have some play.

and yes, engines get broken in by the materials you use in it. nowhere is it an "artificial intelligence." it's like running a car for 100,000 miles on regular oil, then out of nowhere switching to synthetic. you could see some problems from the change, anything is possible. prove me wrong.

 

Yeah, but you'll get the ping later with 93 than you would've with 91, of course. Pretty basic. And why would you necessarily develop ping? It's not a must for any vehicle.

 

assuming it never ever broke from things like spun bearings and blown rods and all that crazy stuff, your engine would at sometime HAVE to develop ping. i don't think 93 octane will keep your engine from developing ping longer. your engine does become accustom to things you run in it, believe it or not. it's not like we become accustom to the daily grinds of life, but when your engine consistantly, day in and day out runs 100,000 miles on 93 octane gas, switching fuel, well, could very well screw with it.

the way i see it, it's like using the same brand of oil in your engine from day one. if i were to put castrol 10w-30 synthetic in my car every single oil change for its life, and you ran castrol one oil change, mobil another, pennzoil another, valvoline another, and assuming our cars and miles and driving styles are exactly the same, my car would probably outlast yours simply because the car becomes tuned to a single specific oil instead of just getting whatever. you can tune your car to 93 octane to the point where that's all the car knows simply because the engine combusts to that certain octane day in and day out for years and tens of thousands of miles. how does that not make sense?

 

Why? There's nothing within an engine that will inherently force it to develop predetonation. There is NO fact behind your statement.
If you get a ping on 91 octane that 93 will stop from happening, then you would never have had that ping in the first place if you had been running 93, given the exact same ping and point of predetonation. There is NO fact behind your statement.
That's hilarious. There is NO fact behind your statement.
Show me some scientific evidence of this. That's preposterous! This is like a theory brought up by a madman (not saying that you're crazy) in that it has no factual basis. There is NO fact behind your statement.
PLEASE tell me you're just totally F'ing with us on this, and that you REALLY aren't serious about this. I'm done with this. There is NOT ANY factual evidence backing up your ideas here.

 

NO, your car doesnt learn how to run on a certain octane by itself, u have to get it tuned for that. its not human its a computer it does what we tell it to do.

 

I'm seriously cracking up at this "logic"......

 

Because it just doesn't.

Next you'll be telling us that you shouldn't buy a used car because it is too accustomed to the last owner and won't handle the change in driving style.

 

I would say run the lowest octane your car can handle without it going to default tables. We have 94 octane around here, but after doing a few weeks with the 94 (I run 91 most of the time) I've seen no difference in mileage nor have "felt" any increase in performance. In theory, the PCM will try to advance timing as much as possible while cruising part throttle. If it detects ping, it will retard timing and try again until it has "learned" the maximum amount of timing part throttle can handle. This in essence can gain some mileage, but you also have to take into account that the PCM also references a fuel/advance table as well to judge this "accurate" and safe range and will not deviate to far from that table. With that in mind, if it's well within the PCM's acceptable range with 91, it WILL not go and try even more advance timing just because you put in 93 or 94 octane as those fuel/timing tables still will weigh heavily on the PCM's learned values.

A car will not mysteriously develop ping over its life. If it does develop ping, no amount of octane increase will magically cure it. If ping develops it's because something is broken and needs to be fixed.

 

91 92 or 93 it dont really matter i use all never felt a differice in peformance or mpg.

 

The only thing that could make an older engine ping is the build up of carbon on the pistons from the combustion process. It will have the effect of making the combustion area smaller and thus boost compression.
The engine is not a spoiled 16 year old girl as mentioned above.
Spun bearings? blown rods? I think chocotaco must own a gas station.
Run whatever GM said to, PERIOD.
An engine is something bound to the laws of physics. It does not get used to any oil or gas. Feed it what the general told ya

 

yes, i must work for a gas station for telling you to use LESS octane and the "spun bearings and blown rods" referece was me saying ping is INEVITABLE if nothing else goes wrong with the engine. people don't experience ping because something else breaks before it pings. if nothing ever breaks, even if it takes a million miles, you'll eventually see ping.

if built up carbon on pistons is causing your pinging, using 93 from the getgo isn't going to prolong that pinging very much, if any at all.

i have always found that sticking to one brand of something is always the best. same brand of oil every oil change, same gas every time. i always buy 91 octane from sunoco (87 from sunoco when i had the old V6, if it's good enough for nascar it's good enough for me). that's all i've bought for 3 years, except once over prom because i needed gas and there was no sunoco cuz i didn't know the area and once when sunoco was all outta gas and i had to drive to philly after work.

plus i love the guy that works there (full service, NJ). i'll never forget when he ran out of all gas but premium.

*in indian accent* "all out of regular. i give you premium 6 cents off! make your car run like NASCAR, VROOM VROOM!"

i see better gas mileage sticking with sunoco all the time and not putting whatever oil is on sale in my car. the parts you use in help dictate how an engine is broken in. if you use castrol every time from the beginning as opposted to mobil from the beginning, it may wear different. if you use any on sale oil from the beginning, it may wear differently.

notice how i've always said FROM THE GETGO here. if the car has 100,000 miles, it probably won't matter what you put in it since you don't know what pervious owners run. if you buy a new car early, be consistant with whatever you do.

you won't see any benefit from 93 octane so you probably won't experience ping any later if ping eventually does develop, but i guess we'll never know for sure will we? i just like having that extra cushion in case it ever DOES develop. once your 93 pings, you're screwed.

 

Carbon build up is combatted by running a top end engine cleaner, at the least GM sells it, but seafoam is the best bet.

I have a 88 305 with 300000 miles and to this day does NOT ping with the damn 87 octane I feed it. There's no mysterious development of ping, there's always a reason and that reason can be fixed. Jumping octanes unnecessarily is not a proper fix to carbon buildup.

 

actually it does.

theres timing trim functions in there, and if ping is regularly detected, it pulls timing, trimming it out...

so it "gets used to" shitty gas or whatever...

when in open loop speed density (aka, what i say, it does, with no fuel trimming) i can see slight differences in the fuel i use... raceway is inconsistant, but i know the HESS by me makes my AFR .20 to.30 leaner then when i fill up at Sunoco (my usual gas)


and thats why i stick with one, just so its more consistent between runs... i also fill up at the exact same pump.... why? because that handle shuts off the same way every time, and i feel that lets me be more accurate when doing the "fill it till the handle clicks" MPG method...

btw the gas i use is sunoco, but thats only because it is literally across the street from where i live.