Do I have to run Premium

[wickedz]

I know turbo your suppose to run Premium, but do you really have to? I have a long trip from FL to Michigan and back to FL again, and wanna do it as cheap as possible . If I have to run 93, then I will.

 

[2gawdtsi]

like maverik gas for example.


thank you for the information knochgoon24
very helpful.

However, i was daydreaming about my car today and a question popped into my mind. When i was reading up on tuning, the ecu cuts fuel according to load calculations, not by boost pressure etc.

With this being true, wouldnt fuel cut be unavoidable even with new injectors/fuel pump.

unless a safc is used? or am i totally off on this.
sorry if im jacking the thread, just a question, and the ops question has been answered plenty of times over.

 

[jeffo]

How would you add injectors without some way to compensate for them? But, yes, if you *could* do that, you would still get fuelcut at the same ~17psi. That's one reason guys do 550's and an AFC, to reduce the airflow Hz by 20%, to raise the fuelcut threshhold. If you were to install a chip with nothing but the 550cc injector compensation, yes, you would still hit fuelcut at the same airflow.

 

[ReYnd]

Bigger injectors than the ECU can compensate for (no idea what size, I'm nowhere near that point yet) need to be factored in when tuning, be it with DSMLink, a chip, or some other engine management solution. An upgraded fuel pump is just able to supply more fuel. If the injectors don't need it, it's sent back to the tank.

Back on topic. I though I read somewhere that "Premium" according to factory specs was between 89 or 91 and 93 octane. The turbo cars can be run with lower grade fuel, but for the love of all things 4g63, don't get into boost at all. It's not worth the risk. I remember someone on here likened going to McDonald's and ordering a Big Mac to every time you fill up our cars. It's not really a big deal. Unless you're like me and have to go get a burger after you fill up anyway. Detonation will kill our cars faster than anything else I know, short of ...collisions.

If you're taking that trip soon, about half-way through you'll notice yourself staying further and further away from positive pressure anyway. It's cold up here, worse up north, and even if the roads aren't bad, you're going to get stuck behind someone who thinks they are for at least a little while. A 17 mile cruise took half an hour. Advice: drive like you don't have a snail.

 

[Nati0nalxCrisis]

using 110 octane gas is only safe if you mix it with high grade pink blinker fluid and run a high flow flux capacitor in your car.

Don't forget to mix it with some boost fluid.

 

[EclipticalGS]

Lets just say even if you got 230 miles on a full gas tank, The 1000 miles from florida to here, (michigan) taking I-65 route hopefully, that 20 cents more per gallon going to premium, say you fill up 14 Gal's every fill up, 20 cents x 14 gals is only $2.80 more every fillup, multiplied by the 4-5 fillups im sure you'll have, maybe more. Thats only roughly $11.20 - $14.00 round trip. Thats 2 stops at McDonalds you may miss out on. Trust me its worth it. This is all estimated on you boosting the shit out of your car, and WOT it the whole way here (230 miles/ gas tank), That is if your DSM will even make it 1000 miles without some sort of problem. Bring tools, and etc.

Stay away from Kentucky's KFC's, and stay away from Tennessee's Wendy's.

Good luck

 

[Smallfry311]

I run 87 in my gst at 14psi and im seems to be doing fine... I heard it only helps with detonation? Correct me if i'm wrong

 

[EclipticalGS]

higher octane reduces chance of knock, to a degree. But why go against those BIG letters that say Premium Only. Like i said, A full fill up is less than $3 difference. I cant say anything though because Im going to E-85

 

[constant_proj21]

Have to keep in mind, how much fuel grades have changed over the years. When my 1992 eclipse was released, 89 was prob premium in most areas. Now does it hurt to use, say 93 ultimate? Not at all, but you can get away with 89, especially on older dsm's.

 

[sag1441]

oh damn. OH well I guess I dont need no spitting and spuddering while on highway hehe. I know Im gonna wanna play.

you said you wanna do it as cheaply as possible. keep your foot out of it. the difference between mileage cruising at 65 and being WOT at anytime is going to affect your wallet way more then a 10 cent a gallon difference in fuel

 

[dsmfa9nutter]

There's a reason it says "PREMIUM ONLY". That money you "save" isn't going to cover the cost of the engine rebuild when you knock like crazy and kill your bearings.

 

[rdejardin777]

also the higher octane you run...the more boost you can put out to...thats one reason drag racers use race fuel.

 

[DSMunknown]

http://www.dsmtuners.com/forums/newbie-forum/12915-regular-premium-fuel-merged.html

 

[evie1g603]

for those of u that are in the midwest and are using 91 octane. if you want to get optimal performance....simply buy the fuel injector cleaner and the octane booster. they're at most gas stations and at every autozone, advance, o'reillys, and napa....not expensive and will boost ## gas to push the car better

 

[DesertTuner]

higher octanes burn better, fuller, and colder (i know that will start an arguement). But basicly no, putting 110 in your car wont make it run better, in fact it might run worse due to the fact its not tuned for it. Your car could go extra rich or lean depending and could actually do damage. If you dont need the racefuel and are not setup for it then stay the hell away from it. 91-93 would be more than fine. Ive tried running pure race gas through a bone stock quad before and seen the damage it can do, now thats a 10,000 RPM machine thats NA but still it can happen just as easily to a turbo 4 cylinder in a car. Seen much worse with exotic OXY fuels like mr9 and 11.

not running a high enough octane will cause pinging or detonation, aswell as pre-ignition which will eventually detroy your pistons, cylinders, heads, first sign will be on your spark plugs but you will hear your motor making sounds it SHOULD not make.

 

[brian_h_2008]

Unless you are set up to tune for the different octane levels use what is recommended.

 

[jeffo]

I run 87 in my gst at 14psi and im seems to be doing fine... I heard it only helps with detonation? Correct me if i'm wrong

And, I will.
The problem with detonation in our cars is that you rarely, if ever, hear it. The ECU hears the knock from the knock sensor, and almost instantly retards the timing to save the motor. Over time, if the ECU hears a lot of knock all the time, it retards the "octane value", a safety measure built into the ECU. If you consistantly put poor octane fuel in the car the ECU learns this, and starts using new timing values that it interpolates between the HIGH OCTANE maps and the LOW OCTANE maps. The lower the "octane value", the more closely to the LOW OCTANE maps you run.
In short, if you are running 87 octane all the time the ECU has reduced your OCTANE VALUE to the point where your performance is severely crippled. If you don't believe me, make a WOT run in your car right before you get gas next time. Then, fill up with 93 octane, disconnect the battery of unplug the ECU for a minute, and then take it for a drive again. I guarantee you will feel the difference.
The only way to really see this in operation is with a good Mitsu logger, like EVOSCAN, where you can log the OCTANE VALUE and see the knock.
Do you still have the BCS solenoid installed in your wastegate line? Do you have a aftermarket boost gauge? Another sign you *should* see is that once the octane value gets too low, or the ECU hears too much knock, it closes off the BCS to reduce the boost 3-4psi.

 

[steve]

for those of u that are in the midwest and are using 91 octane. if you want to get optimal performance....simply buy the fuel injector cleaner and the octane booster. they're at most gas stations and at every autozone, advance, o'reillys, and napa....not expensive and will boost ## gas to push the car better

That's just a waste of money. Those 2-3 points they say they raise the octane mean you just went from 91.0 to 91.3. Big deal.

To make a noticeable difference you have to add gallons of modifier (toluene or Xylene) to a tank of gas.

http://www.elektro.com/~audi/audi/toluene.html


If you have removed the BCS or otherwise modified your car you better be running premium all the time. You have to take a pretty long trip to save enough to pay for a rebuild.

 

[rhodess89]

premium gas is the only way to go on a turbo car its burn slower and more precise.

 

[One Equals Two]

And as I always say, it's not that much more expensive. I spend an extra whopping $2.75 a tank for premium. And as stated above, don't waste your money on "octane booster".

Just run premium, the time your spending thinking about how to use regular is not worth the money. If you were saving $10 a tank, sure go for it, but it's a freakin cheeseburger from Carl's Jr.

 

[Patamos]

my 2 cents. if you have the correct a/f ratio it doesnt matter what octane rating you have. as long as you have enough fuel to compensate for the extra air, what difference would it make whether you have higher octane or not? not saying this to keep you away from being safer than sorry, just saying that i ran 25psi on a 14b, base timing, 87 octane, no knock sensor, and didnt have any pinging whatsoever.

 

[GooeyGus]

IT DOES MATTER.

11:1 AFR on a tune with 93 can run great and 11:1 AFR with 87 can knock like crazy and blow up a piston. Just because the AFR looks good doesn't mean you can just throw in any kind of junk fuel you want and call it a day.

With race gas you can run a much leaner AFR because your fuel is much more resistive to knocking.

You cant just pick one number and call it good for any kind of fuel. With lower octane you will need an AFR that is much more rich, and with higher octane you can run a much leaner AFR.

And, how do you know you didn't have any knocking when you didn't have a knock sensor? By the time you can actually hear it, it's usually way too late. Also, the reason it probably ran fine, is that without a knock sensor your car wont advance ignition timing, so you were probably actually lacking quite a bit of power, but making up for it with a ton of boost (way outside the efficiency curve for a 14b...)

 

[Patamos]

IT DOES MATTER.

11:1 AFR on a tune with 93 can run great and 11:1 AFR with 87 can knock like crazy and blow up a piston. Just because the AFR looks good doesn't mean you can just throw in any kind of junk fuel you want and call it a day.

With race gas you can run a much leaner AFR because your fuel is much more resistive to knocking.

You cant just pick one number and call it good for any kind of fuel. With lower octane you will need an AFR that is much more rich, and with higher octane you can run a much leaner AFR.

And, how do you know you didn't have any knocking when you didn't have a knock sensor? By the time you can actually hear it, it's usually way too late. Also, the reason it probably ran fine, is that without a knock sensor your car wont advance ignition timing, so you were probably actually lacking quite a bit of power, but making up for it with a ton of boost (way outside the efficiency curve for a 14b...)

im sorry. i should have said that it was stock with 7.8:1 compression pistons. i do understand the great importance of octane with boost; especially with higher compression pistons. im also sure that tighter air intake hoses that allowed less air in, helped my situation out as well.

 

[GRAVEDIGGER]

im sorry. i should have said that it was stock with 7.8:1 compression pistons. i do understand the great importance of octane with boost; especially with higher compression pistons. im also sure that tighter air intake hoses that allowed less air in, helped my situation out as well.

Oh yeah, the tighter air intake hoses always help with the 87 octane.WTF